When he turned professional in 1996, Woods signed a contract with Titleist. He switched to Nike balls in 2000, Nike drivers in 2002, and Nike irons before the Ryder Cup that year. His pitching wedge and 3-wood eventually switched to Nike, but he never changed his putter.
So Tiger Woods has signed a lifetime contract with Nike, and he uses clubs specially customized for him by Nike. Basically, what you see on TV now are Nike clubs.
Hope this helps.