It's not quite the same thing, but similar. In money laundering you're introducing dirty money into a legal looking business. You pretend that you washed more

It's not quite the same thing, but similar. In money laundering you're introducing dirty money into a legal looking business. You pretend that you washed more shirts or cars than you truly did, for instance. You pay tax, and from the outside it looks like you have a fully legit, profitable business. On BTC, all transactions are public and traceable. You see Alice pay Bob $50. You see Carol pay Dave $25. You see Eve pay Dave $25. A mixer is an intermediary that makes it less obvious who's dealing with who. Everyone puts money into the pool, the mixer at some points sends payments to the destinations, and it becomes harder to tell who's transacting with who. A mixer can take extra steps to confuse things further, like delaying payments and doing everything in chunks of say $5 at random delays, and rounding amounts, so it's harder to tell from the outside how many transactions there were, and to correlate an input of an odd amount of $123.45 with an equal output. Some mixers offer swapping for freshly mined coins for a higher fee. Unlike laundering, it doesn't really make a transaction look legit. You see Alice send $50 to a mixer, but it's harder to tell who it was truly for.