In the hands of a chef, steak tartare can be a truly beautiful thing. The process seems fairly straightforward: Obtain high quality beef, cut carefully into small pieces, season heavily, dress with a sauce or vinaigrette with balances flavors of salty and sour, then plate with the appropriate accoutrements (usually some kind of crunchy bread or potato product). When done right, it is cold and salty and gamey and has that perfectly tender texture that even the rarest cooked meat can never achieve.
But, please understand: It is ACTUALLY VERY HARD TO MAKE. So, as much as you might enjoy ordering it at restaurants, please learn from the disgusting mistakes so many people have posted on the internet, and don't try this at home.