Generating a key pair will allow you to use secure shell or SSH connections to remote in or remotely access AWS instances. To generate the pair from the EC2 Dashboard, select Key Pairs from the NETWORK & SECURITY group in the left panel after scrolling down:

Give the key pair a name and push Create to save the private key (with a .pem extension) in a secure location on your computer or a USB stick. This key will be required each time you connect to the instance using SSH. The corresponding public key (with a .pub extension) is saved in your AWS account and used to match with the private key when connecting to the instance.