Explain the difference between a single member district seat and an at large seat?

Single Member voting is simply what we do when we cast our vote for a particular candidate. The winner is the one with the most votes. There is no need to make a certain percentage in order to win

At Large Voting is when there would be more than one seat voted on: for example 5 open seats in an election. Usually along the lines of a school board or other types of municipal elections.