A cookie banner is what the visitor sees on your CMP's website. It is a simple tool that informs website visitors about the use of cookies and asks them to accept them. Often it is a simple popup or banner that appears during the first website visit. The popup or banner often then states which cookies the website uses and their function. It also asks whether you want to accept or reject the cookies. So a cookie banner is actually the front end of your CMP.
A CMP is a lot more sophisticated. A CMP is the "invisible" system that records, processes and remembers a visitor's consent. Furthermore, it also helps Web sites comply with privacy laws. So your CMP is actually the backend of the cookie banner.
Explicit permission to set different types of cookies. Visitors to the website must consent to accept the cookies. It must also be possible for the visitor to change about delete the cookies after they have given consent.
The CMP helps you request consent and manage the consents collected. This means you can use the permission for multiple pages and also for future visits by the same visitor.