what is a fork?

i'm started on chess and i wanna know what exactly is a fork

A fork is when one piece attacks two pieces at the same time. If it is a strong fork it will gain material, if not, it won't.

I thought in the same way. And I tend to agree. But recently someone told me that fork is done by knight. Other pieces perform double attack.

I did not differentiate it for years. But if we start to think - it’s very strange “fork” by, let’s say, queen if it attacks pieces at a8 and h1 for instance.

Your all wrong this is a fork

Double attack is fork.

All forks are double attacks. Not all double attacks are forks.

)))

all double attacks are forks, but some are weak forks

Based on what someone told you a few days ago?

That guy is wrong. Most people use "fork" to mean "double attack". Surely there are some who distinguish between the two, but that's not a majority.

A fork is when a piece is attacking two, or more opponent pieces. While it usually refers to an attack against two pieces, it is not limited to that- e.g. the following octuple attack can also be labelled as a fork.

It looks like you've got your answers here, but if you need anything else, I have a blog post on chess terms and their definitions.

Any piece can fork. Even the king.

I did the same. And still I do it but I remember this comment about the difference.

It's a utensil which usually looks like a spoon with 3 or 4 spikes on it