A stage snake is 4 to 64 microphone, guitar, bass, organ anps etc cables in one bundle.
One end has a box that is placed on or near the stage. the other end connects to the mixing board.
Instead or running different cables for each instrument to the mixing board and then back to the PA amps you run one large cable. Plug everything into it going to the mixing board. then the signal from the mixing board is sent back down the snake to the PA amps.