What is RSA Encryption?
RSA is one of the first public-private key encryption algorithms around the world, and is still widely used for secure data transmission today. In this cryptosystem, the public key, which is distributed publicly, is used to encrypt messages; and the private key, which is kept secret, is used to decrypt messages.
RSA is typically used in two manners: data transmission and digital signatures. For example, SSL, a key component of https, uses the RSA algorithm to set up a secure connection between users' browers and the backend server.
For further reading:
• Comparitech
• Wikipedia