There are actually two meanings to the term jeet tek. Literally it means intercepting kick, however it refers to both a kick that intercepts an attack (which in theory could be any kick) as well as the leg obstruction (a block executed as a stiff leg lift). So depending on which tool (the actual intercepting kick or the stiff leg block) it could be a kind of jamming, scraping "kick" or a side kick, round kick, spin kick, oblique kick, etc.
The leg obstruction can be used defensively and offensively. Defensively one can block a kick or an opponent's lunge thus stopping the attack at a fairly early point in its development. Another advantage of this tool is that you take the force of the opponent's kick on the sole of your shoe/foot instead of your shin which can be painful and even injurious (although sometimes this block is necessary for its own reasons). Offensively it can be used to smother potential intercepting attacks executed by your opponent as you bridge the gap. Bob Bremmer spoke of closing the gap with the leg obstruction to set up his lead punch as being one of his signiture tactics, and Ted Wong demonstrates many trapping entries with the leg obstruction in his book comparing Jeet Kune Do with Wing Chun.
