Unusually for a rock guitarist, Beck doesn't use a pick. Instead he uses his thumb, with other fingers controlling the volume knob and the vibrato bar. This gives Beck a very nuanced, expressive sound that almost sounds vocal at times.
Here is the first part of one of Jeff Beck's most famous pieces, "Beck's Bolero":
The rhythm guitar part uses a triplet rhythm that is reminiscent of the bolero rhythm often found in Spanish music: