Study life

   WWW {WORD WIDE WEB} World Wide Web, which is also known as a Web, is a collection of web sites or web pages stored in web servers and connected to local computers through the internet. These websites contain text pages, digital images, audios, videos, etc. Users can access the content of these sites from any part of the world over the internet using their devices such as computers, laptops, cell phones, etc. The WWW, along with internet, enables the retrieval and display of text and media to your device. The building blocks of the Web are web pages which are formatted in HTML and connected by links called "hypertext" or hyperlinks and accessed by HTTP These links are electronic connections that link related pieces of information so that users can access t thihe desired information quickly. Hypertext offers the advantage to select a word or phrase from text and thus to access other pages that provide additional information related to that word or phrase.A web page is...

 What might we at any point instruct you? PC Rudiments: What is a PC? What is a PC? A PC is an electronic gadget that controls data, or information. It can store, recover, and process information. You may definitely realize that you can utilize a PC to type reports, send email, mess around, and peruse the Internet. You can likewise utilize it to alter or make accounting sheets, introductions, and even recordings.Watch the video beneath to find out about various sorts of PCs.Searching for the old rendition of this video? You can in any case see it here. Equipment versus programming Before we discuss various sorts of PCs, we should discuss two things all PCs share for all intents and purpose: equipment and programming.Equipment is any essential for your PC that has an actual design, like the console or mouse. It additionally incorporates the PC's all's inside parts, which you can find in the picture underneath.seeing equipment .Programming is any arrangement of directions that ...

  A firewall is a software or hardware system designed to prevent unauthorized access to an individual computer or network of computers. They are used mostly as a first line of defense to protect your device or network from online threats such as hackers, viruses, Trojans, and worms. Every time you are connected to the Internet, your computer is exposed to all sorts of dangerous programs and malicious people that want to infiltrate your computer to steal your personal information, send spam emails to your inboxes, or use your computer to launch attacks on other computers. A good firewall system blocks attackers from trying to infiltrate your system and prevents your data and information from flowing out to the bad guys. Like a brick wall, a firewall acts as a barrier to protect your computer from online threats Fire walls have a similar function as the drawbridge and the portcullis grate in front of the entrance on a medieval castle-controlling who can go in and out. While a cast...

Hub:- A hub is basically a multiport repeater A hub connects multiple wires coming from different branches, for example, the connector in star topology which connects different stations. Hubs cannot filter data, so data packets are sent to all connected devices, they do not have the intelligence to find out the best path for data packets which leads to inefficiencies and wastage. Types of Hub Active Hub: These are the hubs that have their own power supply and can clean, boost, and relay the signal along with the network It serves both as a repeater as well as a wiring center. These are used to extend the maximum distance between nodes.  Passive Hub: These are the hubs that collect wiring from nodes and power supply from the active hub. These hubs relay signals onto the network without cleaning and boosting them and can't be used to extend the distance between nodes. Intelligent Hub: It works like active hubs and includes remote management capabilities. They also provide flexible ...

 COMPUTER PROGRAMMING LANGUAGES Generally, a language is considered as the medium of communication among people. Likewise, to communicate with computer systems, we use computer programming languages. Usually, we provide a particular set of instructions to the computer to perform a specific task. The set of instructions given to a computer is known as a Program languages. For example, BASIC, C, C++, Java. Such programs are written in languages close to the human languages and are called high level COBOL, Fortran, etc. Each language has its own set of keywords and special syntax for writing the program. But computer cannot understand such languages. Computer understands only binary language that consists of binary numbers that is 0 and 1. So high level programs are converted into low level language program or machine language program using translators. In this chapter, let us study different generations of computer languages. First Generation language-Machine Language Machine Langu...

VARIOUS FILE FORMATS Some of the frequently used file formats are: JPEG It stands for Joint Photographic Experts Group. It is the most widely used file format for pictures. Almost all the digital cameras store photos in this file format as it supports 224 or 16, 777.216 colours. MP3 MP3 is MPEG-1 Audio Layer-3. MPEG is Moving Picture Experts Group It is the most common audio format. Also, most of the digital audio players use this format as the standard format for transfer and playback music Owing to their small file sizes, MP3 files can be easily transferred over the Internet. MP4 MPEG-4 Part 14 or MP4 is a digital multimedia container format. It is most commonly used to store video and audio. A file with the MP4 file extension is an abbreviation for an MPEG-4 Video file. This is a compressed file format MP4 This file format is used for various document and document template file types It is a Microsoft Word Open XML Format Document file. XLSX XLS or xls refers to the Microsoft Exce...

 WHAT HAPPENS IT DOES NOT RAIN FOR LONG PERIOD Sometimes so happens that does not rain in region for a year or more. This leads shortage of water that region causing everywhere. environment drought. So, can say that if does not rain in region for long time causes drought sookha). Drought is period without rains leading to severe shortage of water in the region. happens follows. The soil in the fields is normally moist because it has water in it. The soil continues to lose water by rporation and transpiration. The water lost by soil is usually made up by rains. If, however, it does not rain at all (or the rainfall is very low) for a long period, the o of water from the soil is not made up and hence the soil becomes dry (see Figure 14). Due to lack of rains, the water level in the lakes and ponds also goes down and some of them may even dry up completely. In the absence of rains, no water seeps into the ground and hence the level of groundwater in wells, etc., falls drastically. Due...

 WHAT IF IT RAINS HEAVILY Every place in the world gets rains sometime or the other. The time, duration and amount of rainfall varies from place to place. For example, in some parts of the world, it rains throughout the year whereas in other parts it rains only for a few days in a year. In our country, most of the rainfall occurs in the monsoon season (rainy season). Rains are always welcome. Rains give us many advantages. For example: (1) Rains bring relief by cooling the environment after hot summer days. (ii) The sowing of many crops depends on the arrival of rains during monsoon. (iii) Rains provide water in the rivers and dams of hydroelectric power plants. (fo) Rains fill the lakes and ponds which act as sources of water. Rains are also responsible for the groundwater which gets stored under the surface of earth. When it rains heavily for a long time, we get excess rainfall resulting in too much water all around. The excessive rainfall due to heavy rains leads to many problem...

 Carbon dioxide Carbon dioxide is a colourless and odourless gas. It has a slightly sour taste. Carbon dioxide is moderately soluble in water. Carbon dioxide gas neither burns nor supports burning. Carbon dioxide extinguishes a burning fire. Plants and animals consume oxygen from air for respiration and produce carbon dioxide. Plant and animal matter burns by consuming oxygen from air and produces mainly carbon dioxide and a few other gases. If some material is burning in a closed room, we feel suffocated. This is due to the accumulation of excess of carbon dioxide (and some carbon monoxide) in the air of the room which is produced by the burning material. Air contains only about 0.03 per cent of carbon dioxide gas. Though the amount of carbon dioxide in air is comparatively small but it is a very important component of air. The carbon dioxide gas present in air is important to green plants. Green plants need carbon dioxide gas to make food. In sunlight, green plants use carbon di...

 Waste materials (or rubbish) especially household wastes, are called garbage. It is called 'kole in W Hi Every household produces a lot of garbage (or wastes) daily which is collected in dustbins ps offices and schools also produce garbage or rubbish everyday What does the garbage (or rubbish) This will become clear from the following discussion. We peel off many fruits and vegetables before eating or cooking them. Sometimes cooked food also cunased in our homes and it is called left over food. The leaves of potted plants also keep on falling day in our homes. The peels of fruits and vegetables, left-over cooked food and fallen leaves of ted plants are thrown away as garbage. Every household buys a large number of packaged products such as door (atta), rice, pulses, biscuits, chocolates, milk and oil, etc, which are packed in plastic bags. ardboard cartons, paper wrappers, plastic containers, tirs and many other kinds of packing materials All the packing materials are useless and...

  A large area of land covered mainly with trees and plants is called alaust And a large area of grass covered land used for grazing is called grassland There are few trees or places for animals to hide gland habitats. Due to this speal is important for the animals which live in grassland habitats (so they can nits away from their enemies) For most common purposes, however, the wrous forest and and are used in the same sense. The forest (or grassland) is a habitat Many animals such as lon som elephants deer, en live in forest habitats. There are many features of a lion, a deck, other animals and plant which help them to survive in the forest habitat. The adaptations in lion and deer to the forest habitat are described below. Adaptation of lion The lion is a camivorous animal which eats only the meat (or flesh) of oder animals. The lion lives in a forest habitat The adapted to the forest habitat in the following ways: 1.The lion is a strong, fast and agile animal which can hunt and ...

 The leaf is a thin, broad, flat and green part of a plant which is attached to the stem (or branch). plural of leaf is leaves. A plant has a large number of leaves. Leaves of different plants have differe shapes and sizes, but all of them have the same basic structure. A leaf consists mainly of two parts: lamina and petiole (see Figure 8). Lamina is commonly ke o as leaf blade and petiole is commonly known as leaf stalk. The broad, green part of the leaf is called lan th The thin stalk with which leaf is attached to the stem (or branch) is called 'petiole. There is a mid tr (main vein) in the centre of lamina (or leaf blade). A large number of veins spread out from the mid Rib to all the parts of the leaf. The mid-rib and veins consist of bundles of tiny tubes some of which carry water (and dissolved minerals) into the leaf, and others carry away the food from the leaf. There are minute pores on the surface of a leaf (which are called stomata). Stomata are so small that we cannot ...

  Birds Sparrow, crow, pigeon, parrot, eagle, hen, duck, swan, ove and peacock, are all birds. Birds walk on the ground and igh also fly in air. Some birds (like duck and swan) also swim in my water. Birds walk on the ground by using their hind limbs (see Figure 18). Those birds which swim in water do so by raig pushing against water with their hind limbs which have d trio webbed feet. The webbed feet help the bird in swimming in water. The birds can fly because their bodies are adapted (or modified) for this purpose. The main adaptations which have been made in the bodies of birds by nature to enable them to fly are the following: Their forelimbs are modified to form wings for flying.  Their flight feathers provide a large flat surface which is light but strong. Their bones are hollow and light. Their bodies are streamlined and extremely light. They have powerful flight muscles. Their breastbone is extended (as keel) for the attachment of large flight muscles (which move the ...

 NITROGEN Nitrogen is a colourless, tasteless and odourless gas. Nitrogen gas is slightly soluble in water. Nitrogen gas is not essential for breathing (or respiration). Nitrogen gas neither burns itself nor supports the process of burning. That is, nitrogen does not support combustion. Nitrogen is a very unreactive gas. In this respect, nitrogen is just the opposite of oxygen (which is a very reactive gas. Nitrogen gas present in air is important for living things. All the living things need nitrogen com pounds for their growth. The plants use nitrogen gas of the air to make proteins. These proteins are used by the plants for their own growth as well as for the growth of human beings and other animals. Thus, nitrogen is needed by plants to make protein. Oxygen:- Oxygen is a colourless, tasteless and odourless gas. Oxygen gas is slightly soluble in water. Oxygen gas is essential for breathing (or respiration). We can live for several days without food and water but we will die very...

  RAINWATER HARVESTING One way of increasing the availability of water to overcome its shortage is rainwater harvesting The activity of collecting rainwater directly and store it in big tanks for later use, or making the rainwater percolate into ground more efficiently to recharge the groundwater, is called rainwater harvesting. Thus there are two main techniques of rainwater harvesting: (1) Collection and storage of rainwater in tanks for future use when there is scarcity of water, and (i) To make rainwater percolate into the ground more efficiently by constructing percolation pits and recharge wells so as to recharge (or replenish) groundwater. The groundwater which we take out for our use by digging wells, tube wells and installing hand pumps, comes from the rainwater which seeps into the ground naturally. Now, when too much water is drawn through wells and tube-wells for use in homes, agriculture and industry, the water level in the wells and tube-wells goes down drastically. S...

 Rib Cage If we take a deep breath, hold it for a while and move our hand on the chest, we will find a number of bones in the chest region. These chest bones are called ribs. Ribs are the curved bones in our chest (see Figure 4). Ribs exist in pairs. There are 12 pairs of ribs in the chest of our body. We know that there is a long backbone at the back of our body. There is also a small bone called breast bone in the chest region, in front of our body (see Figure 4). One end of all the ribs is joined to the backbone and their other end is joined to the breast bone. In this way, all the rib bones, -Eye soo a part of backbone, and the breast bone, join to form a 'bony cage" or box-like structure'. The hollow, bony structure formed by the ribs is called 'rib cage' (see Figure 4). Some of the important internal organs of our body such as heart, lungs and liver lie inside the strong, bony rib cage. The rib cage protects the delicate internal organs like heart, lungs and ...

 Cartilage Most of the skeleton consists of hard bones. However, at some places in the skeleton there is a material ich is not as hard as bones and which can be bent. It is called cartilage. So, we can now say that though most of the skeleton is made of bones but it has some cartilage too Cartilage is a firm but flexible material d at some places in the skeleton Cartilage is much softer than bone. Cartilage can be bent without haking. In fact, cartilage is a kind of softer and elastic bone Cartilage is present in the following places in our body : Cartilage Cartilage is present in the pinnae of ears (upper part of ears) Cartilage is found at the end of nose. Cartilage is found on the end of bones where they meet one another at a joint Cartilage is also present (as cartilage discs) between the vertebrae of backbone. The upper part of our ear is called pinna and the lower part aled ear lobe. If we press the pinna of our ear and the ear lobe been our fingers, turn by turn, we will fin...

 The food which we eat during the whole day is called our diet. A diet consists of many food items made from cereals (like wheat and rice), pulses, fruits, vegetables, meat, fish, eggs and milk, etc., which supply all the nutrients to the body. The diet which contains adequate amounts of all the nutrients such as carbohydrates, fats, proteins, vitamins and minerals (sufficient for the normal growth and development of the body), is called a balanced diet. A balanced diet also contains sufficient amount of water and roughage. Some food items are rich in carbohydrates, some are rich in fats, while others may contain more of proteins, vitamins and minerals. No single food item can provide us all the essential nutrients in adequate amounts. So, in order to make a balanced diet, we should include a number of different food items in our daily meals which, taken together, provide us all the nutrients in adequate amounts. We should also drink sufficient water and eat roughage-containing foo...

 FATS Like carbohydrates, fats also provide energy to our body. In fact, fats provide us twice as much energy as that provided by the same amount of carbohydrates. For example, a little butter (which is a fat) provides us much more energy than a large slice of bread (which is a carbohydrate). Butter, ghee, groundnut oil, mustard oil, sunflower oil and coconut oil are the common fats used by us in everyday life. Fats are the richest source of energy but they are more expensive than carbohydrates. Since both, fats as well as carbohydrates provide energy, therefore, the foods containing fats and carbohydrates are called 'energy giving foods'. Fats are supplied to our body by many foods such as: Butter, Ghee, Milk, Cheese (Paneer), Oil (Groundnut oil, Mustard oil, Sunflower oil and Coconut oil, etc.), Egg yolk (yellow of an egg), Meat, Groundnut, Cashew, and Soybean. Please note that fats and oils are similar substances, the only difference being that fats are solids at room temper...

 Human Brain  Is reflex action the only function of the spinal cord? Obviously not since we know that we are thinking beings. Spinal cord is made up of nerves which supply Information to think about. Thinking involves more complex mechanisms and neural connections. These are concentrated in the brain, which is the main coordinating centre of the body. The brain and spinal cord constitute the central nervous system. They receive information from all parts of the body and integrate it.We also think about our actions, Writing, talking, moving a chair. clapping at the end of a programme are examples of voluntary actions which are based on deciding what to do next. So, the brain also has to send messages to muscles. This is the second way in which the nervous system communicates with the muscles. The communication between the central nervous system and the other parts of the body is facditated by the peripheral nervous system consisting of cranial nerves arising from the brain and ...