Cooking steaks is something of an artform; their small size makes them prone to dry out during cooking. There is much debate between how people like their beef prepared and just a couple of minutes on the grill or in the grill can make all the difference in delicious flavour and texture or complete failure.
Raw steak is completely uncooked. If you order a steak tartare or beef carpaccio in a restaurant, they will have had no cooking time at all, although in the case of steak tartare, the minced beef will have been mixed with herbs, capers and raw egg. Rare steak is cooked for one to two minutes per side to sear the outside and is then left to rest at room temperature for six to eight minutes.
Raw beef is a bright, red colour. Rare steak is red in the middle and a greyish-brown colour on the outside. Blue, which is the term that applies to a steak somewhere between raw and rare, is a barely cooked steak on the outside that is bright red on the inside; nothing at all to do with the colour blue.
Steaks become firmer the more they cook. Therefore raw steak will be soft and almost mushy, think of the texture of mince for instance. A rare steak will be a little firmer on the outside but will still be soft to the touch and have a little bounce.
Raw steak is hardly served without some kind of herbs; in steak tartare, for example, you can taste the pickled capers, lemon juice or the heat of Dijon mustard or Worcestershire sauce. Without these ingredients it tastes slimy and has an unpleasant aroma. Raw beef is also hard to digest and is more likely to contain bacteria than cooked beef. Rare steak has more flavour as the outside will be slightly crisp.