OSI MODEL

Open System Interconnection (OSI) Model was Introduced in 1984. It has seven Layer which help computer to communicate with other computer over the Network. Its read from Top to bottom

7. Application Layer : It is responsible for message formatting like when we open internet explore we work on application layer
6. Presentation Layer:- It help to decrypt or encrypt the message or compression, decompression

5. Session Layer : It allows authentication or permission to make session restoration

4.Transport Layer:- End-to End Control error or make divide data into packets.

3.Network Layer :- It allows network addressing, ip addressing or routing , forward packets.
2.Data Link Layer : It detects error or flow control on physical link
1. Physical Layer :  Physical medium (cable or Lan card) method of representing bit, like hubs, or physical cable.

HOW TO RECOVER DELTE DATA FROM HARD DRIVE

When you delete you hard drive data or format your hard drive your data has not deleted permanently you can recover your HD Data with easily. There are lot of software available  in the market which can recover your data and Stellar Phoenix Windows Data Recovery Tool is the best tool to recover your HD Data . You can buy Sellar Phoenix Windows Data Recovery Tool
Stellar Phoenix Data recover

INCREASE INTERNET SPEED BY USING FIREFOX

If you are using Firefox browser so you can increase it speed by manually just type about:config in the address bar where you enter the website.

Now Search for Network http.pipelining.maxrequest . You can also enter this value in filter option now  double click on it and Change it value from 32 to now search network.http.proxy.pipelining double click on it  and make its value to true .

ENJOY THE SPEED......