Curious about TLS

Doing some pcaps and some personal study/notes but haven't found a good explanation as to why on EAP-TLS auth or even when talking to a web page covered by a TLS cert the captures show Change Cipher Spec. Usually it's fine, in my recent lab of EAP-TLS its still authenticating fine despite that message. But I was curious why it happens. I thought the ciphers were agreed upon prior to the authentication. And in some cases I've seen the change in ciphers cause the connection to the web page to drop over and over afterwards.

Anyone know much about the particular purpose of that packet?

Thanks