There are two very different kinds of coconut milk. Until recently, the term applied primarily to a thick and fat-rich canned product that’s perfect for making peanut sauce and Thai curries. You can think of canned coconut milk as coconut cream, since it’s far thicker and more fatty than anything that comes from a cow.
Recently, as the market for dairy alternatives has taken off, a non-dairy milk made from coconuts and packaged in traditional milk cartons has also become commonplace. This kind of milk is perfect for cooking needs and for pouring on your morning cereal.
If you’ve got access to coconuts, you can make either sort of milk in a Vitamix or Blendtec. Note that these milks require mature coconuts with substantial amounts of meat. Young coconuts contain sweet coconut water and have virtually no meat, so they’re unsuitable for producing both coconut creams and coconut milks.