What is a mergeset in Kaspa?

A mergeset is the collection of blocks in a block's anticone that the Kaspa network considers during consensus processing, with the selected parent excluded.

In Kaspa's blockDAG, blocks can exist alongside one another rather than strictly one after the other — the anticone is the term for these side-by-side blocks relative to any given block. When the network processes a block, it must decide which of those neighboring anticone blocks to include in its ordering pass; the mergeset is exactly that chosen subset. The selected parent is the block's primary direct link and is already handled separately, which is why it is excluded from the mergeset.

For a beginner, the mergeset is worth knowing because it is the mechanism by which Kaspa brings parallel blocks into consensus rather than ignoring them — it is what makes the blockDAG more than just a regular chain.