SSL (Secure Sockets Layer) lookup is a process that involves using a computer program to check the SSL certificate of a particular domain name. An SSL certificate is a type of digital certificate that is used to establish a secure, encrypted connection between a web server and a web browser. It is used to protect sensitive information, such as login credentials and credit card numbers, as it is transmitted between the two. To perform an SSL lookup, you would typically use a tool that is specifically designed for this purpose, such as a website or software program. The tool would take a domain name as input and then return information about the SSL certificate that is associated with that domain name. This information can include details such as the issuer of the certificate, the date it was issued and expires, and the encryption strength. SSL lookup can be useful for a variety of purposes, such as verifying the identity of a website, checking the security of a connection, or detecting fraudulent websites.