OpenSSL is a cryptography library that supports the TLS protocol. It is used as part of the Certificate Signing Request (CSR) for SSL certificates on your web hosting server. Your OpenSSL version will affect the algorithms and protocols supported.
The instruction to display OpenSSL version is:
openssl version
You must run this instruction from the command line of your Operating System (OS). For Linux, open a terminal window using the CTRL+ALT+T key combination. For Windows servers, open the search box and type CMD to access the command prompt.