Fantasy football drafts can be snake, auction, or straight. An autopick draft is a type of snake draft where the players do not take part in the live drafting process. Rather, the draft is automatically carried out with each team taking the highest ranked player when their team is on the clock.
General managers can set their own draft rankings so that they have control over which players they get. In ESPN leagues, players can also specify the position they want to draft in a given round. Doing so will cause the player's team to draft the highest ranked player of that position in the given round.
General managers can also set a maximum and minimum number of players at each position to draft.
The general rule of thumb for fantasy football drafting is to try to get a running back or wide receiver in the first round. This is because there are very few highly effective running backs and wide receivers, whereas there are a lot of quarterbacks who will generate a lot of points in a fantasy league. With this in mind, many players set their position preference to running back for their first round pick. This will cause the computer to pick the highest ranked running back in the first round.
In the other rounds, the position preferences depend on personal strategy as well as league scoring settings.