What does “aller chercher” mean in French?

On its own, chercher is to look for something. Put a verb of movement in front and the searching disappears: aller chercher is to go and get, and venir chercher is to come and collect. Je vais chercher les enfants à l’école is the school run, not a hunt. Je vais chercher la télé means the television is about to be carried into this room.

The pattern is worth having in three ready-made forms: va chercher ! (what you say to a dog, and to a child sent for the bread), passer chercher quelqu’un (to swing by and pick someone up), and venir me chercher à la gare (to meet my train). Only bare chercher keeps the searching sense — je cherche mes clés.