Think of a database as an online index, like the one in the back of a book.
You use both to look up a topic to see where there is more information about your subject.
1) They are all protected by licensing agreements and copyright - lots of legal issues.
2) Copyright and licensing also means you have to pay for a subscription (your Tech Fee) and use a password to see the information.
3) Librarians try to make it as easy as possible to login and to search for what you need-- but you have to use the library website to get to the database, so the company that owns the copyright knows you have paid for access to their databases.