Torches were portable lights used to illuminate dark places. They were carried with lanterns and weapons by the group that came to arrest Jesus in Gethsemane.
John records that Judas came with a band of men and officers carrying lanterns, torches, and weapons when Jesus was in the garden.
Torches were useful even at full moon because the Kidron valley contained deep shadows, caves, grottos, and other places where a fugitive might hide.