How to get security token in salesforce?

1. What is the Salesforce Security Token?

 The security token is designed to increase the security between the end user and Salesforce.com servers, reducing the chance of your account being hacked or accessed by an unauthorised user.

 Your Salesforce security token should have been emailed to you when you set up your Salesforce account or the last time you reset your password.

 When you access Salesforce from an IP address that’s outside your company’s trusted IP range using a desktop client or the API, you need a security token to log in.

 + The security token is a 24 character, automatically generated
      Ex: 17PH0TIvfuVxG6s9x4wza3vc
 + Security tokens can be manually re-set at any time at the users request
 + Security token’s are case sensitive
 + A users security token will change automatically when their password is updated
 + Each security token is unique to a specific user and cannot be re-used

 2. Resetting Your Security Token in Salesforce 

Step 1: Sign in to salesforce https://login.salesforce.com/ 

Step 2: Go to Username => Click My Settings
      Or: Click Here (https://ap2.salesforce.com/ui/setup/Setup?setupid=PersonalSetup)

Step 3: In My Setting => Select Personal => Select Reset My Security Token => Click Reset Security Token => Salesforce will send a new security token to the email address for your account.

Step 4: Sign in your Email and copy your token