Lob is short for 'long bob', and refers to a hairstyle in which the hair is cut to fall somewhere in the range of shoulders to collarbone; some definitions put it below the chin but above the shoulders, but this does not match modern usage.
Lob cuts are so common that they are often not named; this is just a good length for hair, and you don't need a hairstylist or technical terminology to know this. Long enough to tie back or braid, short enough that it doesn't tangle and isn't hard to comb, easy to put up, takes very little fixing when you put it back down.
That said, a lob can have any variation you might find in any bob, or any hairstyle; highlights, colors, layers, feathering, etc. A lob is, at the time of this writing, most often seen with highlights or balayage, no bangs, and a center part.