Briefly explain how the electoral college functions in choosing the american president

The Electoral College:

There are 538 votes, because of the 100 senators and 438 representatives.
Each state has a certain amount of votes, based on the amount of senators and representatives they have. The people vote for the president, and if there's a majority in that state, that certain amount of votes goes to that candidate's side. If a candidate gets a majority of votes, they win.

However, it actually isn't the people doing the voting. There are electors, who are voted on by the people actually, who pledge to vote for these people. They can of course vote for someone else, which is a major problem.