I'm not going to write the whole paragraph for you, however, I will provide some details. Primaries occur for each party in every state where registered voters cast their vote in favor of one candidate specifically from that party in which they are registered to. States will announce the candidate who obtained the majority vote for their selection as that party's nominee during the convention. These conventions are held in a two select cities for either party. These conventions conduct debates and will host the eventual nominee.
Now that the nominees for both parties are selected, the election for president begins. The Electoral College is made up of delegates from all states where they can submit their own vote, however in some states the delegate must submit their vote in accordance to the who won the majority. The House of Representatives can play a major role in deciding the President if the Electoral College is in deadlock or no candidate has obtained a majority vote.
Hope this helps. If I got something wrong please comment with a correction.
