SSL termination SSL offloading SSL acceleration

• SSL termination refers to the process of decrypting encrypted traffic before passing it along to a web server.

What is SSL termination?
decrypting all that encrypted traffic takes a lot of computational power—and the more encrypted pages your server needs to decrypt, the larger the burden.
SSL termination (or SSL offloading) is the process of decrypting this encrypted traffic. Instead of relying upon the web server to do this computationally intensive work, you can use SSL termination to reduce the load on your servers, speed up the process, and allow the web server to focus on its core responsibility of delivering web content.
https://www.f5.com/services/resources/glossary/ssl-termination

• SSL acceleration refers to off-loading processor-intensive SSL encryption and decryption from a server to a device configured to accelerate the SSL encryption/decryption routine.

https://www.f5.com/services/resources/glossary/ssl-acceleration

• SSL offloading is the process of removing the SSL-based encryption from incoming traffic to relieve a web server of the processing burden of decrypting and/or encrypting traffic sent via SSL. The processing is offloaded to a separate device designed specifically for SSL acceleration or SSL termination.

SSL termination is particularly useful when used with clusters of SSL VPNs, because it greatly increases the number of connections a cluster can handle.
https://www.f5.com/services/resources/glossary/ssl-offloading