What is meant by a component of a vector?
Consider a vector
If you want to describe it to, say, a friend you can say that has a "modulus" (=length) and direction (you may use, for example, North, South, East, west...etc.).
There is also another way to describe this vector.
You must take your vector into a reference frame to have some numbers related to it and then you take the coordinates of the tip of the arrow...your COMPONENTS !
You can now write your vector as:
In 3 dimensions you simply add a third component on the