The problem it solves
A golf ball hit into a green arrives from height at speed, and it leaves a small crater in the turf — usually called a pitch mark or ball mark.
Left alone, that mark takes two to three weeks to heal and leaves a dead patch that deflects putts in the meantime. Repaired promptly, it recovers in a day or two. On a busy course with a hundred rounds a day, the difference between golfers who repair their marks and golfers who don't is the difference between a smooth green and a pockmarked one.
How it's used
It's not what most people assume. You don't lever the middle of the mark upward — that tears the roots and makes it worse.
The correct method is to push the prongs into the turf at the edges of the mark and gently work the surrounding grass inward toward the center, going round the mark, then tap the whole thing flat with the base of a putter.
It takes about ten seconds. The technique matters enough that most golf courses print it on a sign near the first tee.
Divot or pitch mark?
Strictly speaking, the tool is named slightly wrong, and it's worth knowing if you want to sound like you know what you're talking about.
A divot is the strip of turf a club takes out of the fairway when hitting a shot. A pitch markis the dent a ball makes landing on a green. The tool repairs pitch marks, but "divot tool" is what everyone calls it, including the manufacturers.
Why it's a good gift
Three reasons, and they stack up better than the price suggests:
Every golfer needs one.It's basic etiquette rather than optional equipment, in the same category as replacing a divot on the fairway.
They get lost constantly.It's a small metal object that lives in a pocket and gets put down on greens. Golfers lose them the way people lose lighters.
Most golfers are using a free one. The typical divot tool was handed out at a tournament or came free with something. A proper one with a brand on it is a small, genuine upgrade — which is exactly what makes an inexpensive gift work.
What to look for
Most divot tools now combine several functions: a magnetic ball marker that clips into the body, a brush for cleaning club faces, a groove cleaner, and sometimes a bottle opener.
The things that actually matter are that the prongs are sturdy enough not to bend in firm ground, and that any ball marker is properly magnetic rather than a friction fit — the friction ones fall out.
Divot tools sit comfortably in the under $25 bracket, and they're one of the better items to combine with a towel and a glove for a fuller gift.