You might have heard some times that not to give your password or credit card information or any other sensitive information on public computers or on Msn, yahoo etc chats.The reason why you might have heard that the Hackers have some ways to you would have probably heard that hackers have a way to steal your your credit card numbers , passwords etc.
A hacker can use different types of attacks such as Packet sniffing or ARP Poisoning to steal your sensitive information

Secure Sockets Layer (SSL) is the most widely used technology for creating a secure communication between the web client and the web server. You must be familiar with http:// protocol and https:// protocol, You might be wondering what they mean. HTTP protocol is used for standard communication between the Web server and the client. HTTPS is used for a secure communication.

Cryptography


If two users want to have a secure communication they can also use cryptography to accomplish it

For example:

TFDVSF=Encrypted Text

SECURE= Decrypted Text

You might be wondering how i Decrypted it, Here i have used Algorithm=+ for the communication and the key is "1", What comes after S is T so as you can see that S is converted into T, What comes After E is F to letter E from the word secure if converted into F and so on, To help you understand this more better I am adding a Video



So If the hacker starts sniffing from between he will get Encrypted text and as the Hacker does not know the keys so he cant decrypt it, but if the attacker or hacker is sniffing from the starting point so he will get the key and can easily Decrypt the data

Standard Communication VS Secure communication

Suppose there exists two communication parties A (client) and B (server)

Standard communication(HTTP)


When A will send information to B it will be in unencrypted manner, this is acceptable if A is not sharing Confidential information, but if A is sending sensitive information say "Password" it will also be in unencrypted form, If a hacker starts sniffing the communication so he will get the password.

Secure communication (HTTPS)

In a secure communication i.e. HTTPS the conversation between A and B happens to be in a safe tunnel, The information which a user A sends to B will be in encrypted form so even if a hacker gets unauthorized access to the conversion he will receive the encrypted password (“xz54p6kd“) and not the original password.

This mean that even if the Hacker Sniff the Communication between the client And Server even then he/she would not be able to get the Sensitive information.