When you are connecting to services on the Internet you really want to be sure that you are talking to the correct server. Certificates ensure that communications are secure.
What is a certificate
A certificate is a small file containing a key that is used to confirm the identity of the people or services communicating with each other over a network.
Installing the CA certificate
If you visit a website using a University certificate then your browser may complain about it. The solution to this is to download and install the University's Certificate Authority (CA or root) Certificate in your browser.