what is virtual machine?

Virtual Machine is just like a machine or operating system(s) installed into your operating system. It just work like an another computer. It is very useful when u need another operting system and u donot want to replace your present operating system or u donot want to spend a dedicated partition or extra space. It takes few GB space from your hard disk and physical memory and give it to the virtual machine. After installation of Virtual Machine inside your current operating system using a software like VMware or Virtual box, you can safely browse internet without letting others know your IP address. It is a very good method to hide your IP.
I will be shortly writing methods to hide your IP address.
good comments are always welcome!

DNS- Domain Name Server

What is DNS?
DNS or Domain Name Server is the server which maps the Domain name into its corresponding IP address. As we all know that every website or URL has a domain name, not only that; the email address also has its corresponding IP address. When we send email to any person, we know the email address but we donot know their IP so, it is the DNS who maps the email address to the corresponding IP adress and sends the email to the corresponding host of that IP because TCP/IP uses IP address to identify the host in any network.

Do email me if u want to know about anything.. vikash100dhn@gmail.com

How to hack gmail, facebook or other email id's password?

Although it is not easy to hack any password but if the victim is not aware of the security facts then their email id's can be easily hacked. Here are few methods to hack email id's:
Phishing:
you can easily hack one's email id using phishing. It is the method of making a fake webpage of facebook, yahoo, orkut, gmail etc. and uploading it on free hosting websites like my3gb.com and then sending the link to the victim. when the victim tries to login, its username and password will be redirected to the attacker's file which is uploaded on the server.

social engineering:
In this method the hacker tries to find out the security questions of the victim by using social engineering skills. Social engineering means finding the facts of the victim like hints for the password or the security questions without letting them know.

By using Keyloggers:
we can silently install keyloggers on their computer if physical access is available on their computer. Or by using your own computer and asking them to login and your computer will moniter the keystrokes and then find their username and password.
other ways are like DNS poisioning or using password attacks. In LAN we can use ARP poisioning or packet Sniffing.

XSS- Cross Site Scripting vulnerability/ Cookie Stealing

introduction:

This vulnerability allows for an attacker's input to be sent to unsuspecting victims. The primary usage for this vulnerability is cookie stealing; if an attacker steals your cookie, they can log into whatever site they stole your cookie from under your account (usually, and assuming you were logged in at the time.)

what is cookie?

A cookie, also known as a web cookie, browser cookie, and HTTP cookie, is a piece of text stored on a user's computer by their web browser. A cookie can be used for authentication, storing site preferences, shopping cart contents, the identifier for a server-based session, or anything else that can be accomplished through storing text data.

Cookies may be set by the server with or without an expiration date. Cookies without an expiration date exist until the browser terminates, while cookies with an expiration date may be stored by the browser until the expiration date passes. Users may also manually delete cookies in order to save space or to address privacy issue .

VPN and PROXY

VPN
VPN stands for virtual private network. A VPN keeps your wireless communications safe by creating a secure "tunnel," though which your encrypted data travels. These tunnels cannot be entered by data that is not properly encrypted. Not only is data encrypted when you use a VPN, but the originating and receiving network addresses are also encrypted. This adds an extra layer of security.

PROXY
Proxy sites enable you to bypass your own Internet provider and browse through the proxy web site. All that you have to do is type the web site address you would like to visit in the form they provide, and start browsing. Once you keep browsing using that form, you are protected and your real IP address is not being logged.