For a 600-700 rated person, what would be more valuable, bishop or knight?

I've heard that the bishop is more valuable than the knight, but I've always thought that it was for only high-rating games. Is there a difference with a lower rating?

Even at higher ratings, the bishop is only slightly better than the knight. At lower levels, the difference is barely anything. You should be trading based off of the position that will come out of the trade and if it betters your position.

I like the bishop...

As a whole in general, players do seem to find bishops more useful than knights based on many games.

However, this depends on each specific position, and actual results vary from player to player. I have had more successes with knights than bishops and a lot of my downfalls are, in fact, due to knights.

I find knights more useful than bishops. You can only stay in a specific coloured square when you have a bishop you also can't block the knights attack; you can only kill the knight or move away to win. Queen also can't move like a knight so knights can't be replaced but bishops can.

I think in lower rating its much easier to get powerful forks with knight because lower rated players rarely think about king forks!

A knight on the 5th or 6th rank, on the central files, protected by a pawn, which cannot be exchanged, is extremely powerful. Probably worth a rook. 2 bishops in an open position are extremely powerful. A queen and knight attacking together are extremely powerful. Bishop + pawns is usually much better than knight + pawns in the endgame. It all depends on the specifics of the situation. 

For a 600-700 I would say knight because they sometimes misjudge or can't see their movement as well as a bishops simple diagonal, however in the higher level it depends on the position but yes, bishop pair are stronger than the latter. 

in the starting position the bishop is worth maybe  1/8 of a pawn more than a knight.

But one thing you should learn is the value of the knight and bishop and other pieces goes up and down [usually slightly] with each move. [chess is a hard game]

The bishop is considered a tad stronger. But at lower levels knights might create more damage due to knight forks.

Back when I used to play a lot of bullet games, I found the knight more useful than the bishop, because of how "tricky" it is. I would often win knight vs rook endgames with equal pawns if both our clocks got low.

So I think the same thing might be true with low rated players.

Obviously Knight because in 700 - 800 rating many players miss Knight forks also Bishop forks are very very rare !!

@TarunBeast I think your forgetting that the bishop can pin..