The Balancer (also known as the Distributor, or the Merger or Splitter under their respective contexts) is used to merge 2 belts into 1, split 1 belt into 2, or evenly distribute the contents of 2 belts.
A balancer has two inputs at its back and two outputs at its front. It will alternate which output incoming items are sent to, starting with its left. If one of the outputs is clogged, it will always output to the unclogged output.
For the most part, both inputs are treated as the same. If items enter both inputs at almost the same time, the balancer will prioritize the left input, and it will also only flip its chosen output once instead of twice. This allows for the contents of two full lines to be evenly mixed.
The Compact Merger (also known simply as the Merger) is used to merge 2 belts into 1. Unlike the balancer, it is only one tile large.
A compact merger has an input at its back and at one of its sides, and an output at its front. It will send items entering either input to its output.
If items enter both inputs at almost the same time, the compact merger will, regardless of its own orientation, prioritize inputs coming from the north, then the east or west, and then the south.
The Compact Splitter (also known simply as the Splitter) is used to split 1 belts into 2. Unlike the balancer, it is only one tile large.
A compact splitter has an input at its back, and an output at its front and at one of its sides. It will alternate which output incoming items are sent to, starting with its front. If one of the outputs is clogged, it will always output to the unclogged output.