Zerg wall is a tool to slow down SpeedZealot pushes, stop Vultures, and Zergling run-by. It is a must in modern ZvP and can be used when Terran does 1/1/1 in ZvT.
Gateway-Cybernetics Core Relationship
Cybernetics Core-Forge Relationship
Middle location on Circuit Breakers: Vulture Wall
Top right location on Circuit Breakers: 2 Goon Vulture wall
Main base: Wall around mineral line against Vultures
Try to make your wall with gaps further from the ramp so Zerglings can't just run through your cannons into the main. It is mostly possible to create a 2-3 Zealot-Ling gapped wall. Zerglings cannot surround, thus losing effectiveness of their numbers.
Bottom left location on FS: Gate-Forge 2 gap wall in the natural
Bottom left location on FS: Gate-Gate 2 gap wall in the natural
Top right location on Circuit Breakers: Buying the time with pylons, just one pylon is enough to change the course of the battle. If he has no reavers, you can just snipe his dragons with scarabs behind the safe cover
Top left location on Circuit Breakers: Top of the Robo-Mineral is the only Protoss combo that can block scarabs