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Internet Protocol address also known as IP address is 32 bit binary number which provides a unique identity to a computer connected to the computer network and allows communication between them. In simple words the  IP address is the unique identity to find your computer on a network just as our home address is used to locate us. IP addresses are usually in binary format but for human understanding they are displayed in digital formats. IP address is 32 bit number where a group of four numbers called as octet are separated with each other using a dot. Each number can be in a range of 0 to 255.

For example:

IP address is in digital format                 128.48.52.3

IP address is in binary format                 10000000.00110000.00110100.00000011

This 32 bit IP address consist of two parts net (prefix) and Host or Node (suffix) where net section of the IP address is the address of physical network to which computer is connected and host section of the IP address is an address (unique identity number) of the computer on that network. We can assign random IP address provided it is unique and it is in small computer network, whereas registered IP addresses are required to connect a private LAN network to internet in order to get unique IP address. Internet Service Provider maintains a pool of unique IP address from where we can register our required IP address. Some of the IP address are reserved and cannot be allocated

For example:

IP address 0.0.0.0 can only be used for Default network (all packets which doesn’t have any explicit routes defined in routing table are send to destination network by Router) and IP address 255.255.255.255 is allocated for Broadcast (Sending messages from one sender to all the nodes on the LAN network).

In order to visit or communicate with a website remembering its IP address is very important. Remembering the IP address of each and every website is a very tedious job in order to avoid this we can use name of the web address.This can be done using Domain Name System, this converts web address name into IP address.

For Example:
IP address of yahoo.com is 69.147.125.65 remembering yahoo.com is easy as compared to remembering 69.147.125.65 same is the case for emails remembering email@yahoo.com is easy than remembering email@69.147.125.65

In Domain Name System, DNS Server are used to provide the IP address of the corresponding web address name.  The application which wants to convert the web address name into IP address acts as a client and send a DNS request message containing the web address name to the DNS server .Here DNS server fetches the web address name from the message and convert it into corresponding IP address and return the IP address to the application as a reply.

IP address can be static and dynamic.
Static IP Address: Static IP address is manually allocated to system. The administrator of the network has to manually configure the Name servers, default gateways and IP address on the computers connected to network. On large networks allocating Static addresses is a tedious job as the administrator has to configure address on each and every computer connected to the network, so static IP address are usually used in small networks. Usually Network Devices like Switches, routers etc uses static addresses. Static address assignment is generally used in the networks which needs more security and address tracking. As static address is manually allocated network security breach is minimum. Static address is mostly used in web servers.

Dynamic IP Address: DHCP servers are used to dynamically assign the IP address to the computer. The administrator defines the address pools and required parameters to the computer and enables it to get the address dynamically. Dynamic address allocation method is used in the networks which do not require the same address for performing various operations. As soon as the computer is logged in the network it acquires the IP address without concerning the user about the network configuration. Dynamic IP addresses are mostly used in large computer network. Dynamic address assignment can be a solution to the large computer networks where renumbering will occur.

Computer is a machine which accepts the data or information in raw formats (digital format) process this data according to the given order of instructions and produces the desired output. Computer is composed of four main components those are Memory, ALU (Arithmetic and logic unit), Control unit, input and output devices (Peripheral devices). These components are interconnected to each other with Busses (group of wires).

Memory is a collection of registers which are used to store the processed data. Reading and writing data in Memory takes very less time as compared to Main memory. In order to increase computer speed, data which is needed most frequently is stored in this memory. There are two types of memory. First is Random-Access Memory (RAM) second is Read Only Memory (ROM). RAM can be modified but ROM is permanent i.e. anything written in RAM can be changed whereas nothing can be written or added or deleted in ROM. ROM is pre loaded with data at the time of manufacturing. Initial start-up instructions of computer are stored in ROM.
RAM is volatile (contents gets erased when power is turned off) whereas ROM is non volatile.

ALU (Arithmetic and Logic Unit): ALU is used to carry out the Arithmetic and logical operations on the data.
Arithmetical operations such as addition, subtraction, Multiplication, division, trigonometry functions (sine, cosine, tangent) and square roots are performed by ALU on integers and floating point (real numbers are depicted as floating point) within no time. Logical operations such as AND, OR, XOR and NOT can also be performed easily.

Control Unit:
The Control unit is the brain of CPU. It controls the working of the other devices. When the program is given as the input through input device the control unit read it and decodes the program and based on instructions either sends sequence of signals to the other devices stores the resultant data into memory. There are different types of control units,one is the hardwired control unit the other one is known as microprogrammed control unit. Hardwired control units are made of digital circuits; once the hardwired control unit is constructed it cannot be modified whereas microprogrammed control unit can be modified according to the instructions in microprograms.

Memory, ALU, Control Unit together constitutes CPU (Central Processing Unit).

Peripheral Devices (Input and output devices): Input and Output devices are required for establishing communication between the computer and user. Input devices as the name indicates are required to provide information to the computer and output devices are used to display information to user. Keyboard , Mouse , Microphone, Joysticks ,scanners digital cameras ,Barcode Readers, Webcam ,Laser rangefinder are known as input devices ; Monitor (Display), Printer and Speakers are known as output devices.

ENIAC (Electronic Numerical Integrator And Calculator) was the first digital computer which was invented at the University of Pennsylvania by J. Presper Eckert and John Mauchly. It was a really huge machine made of 18000 vacuum tubes, weighing almost 50 tons and occupied area of 1,800 square feet. Whirlwind machine was the first digital computer with magnetic core RAM and Real-time graphics introduces by MIT. Electronic Delay Storage Automatic Calculator (EDSAC) was the first stored program electronic computer and first computer that supports graphical computer game. It was invented in England at University of Cambridge.Kenback-1 was the first personal computer introduced in 1971. In Kenback-1 sequence of switches were used for inputting data and output was display by turning on or off the sequence of lights. Osborne I was the first compact computer made by Adam Osborne in 1981 which had 5 inch display CRT, two floppy drives with memory of 64 KB and a modem. Today’s computers are much faster and more capable than early computer machine with very less occupied space. Now a day’s computers (P Cs) are as small as plam tops, some of them can be easily be fitted in mobiles too. Embedding computers are seen in every device ranging from toys to washing machines and from defence purposes like aircrafts to industrial purpose like robotic manufacturing machines.