Well it depends on what you are doing. You don't provide much info

If you have a simple array of x and y coords where each cell hols one object then obviously before you move to a new cell you check if something else is in the next square.

You could also test the distance between objects - when they are very close then treat as a collision.

Another way would be to have a rectangle surrounding all of your objects. When you move check to see if one or more points fall within a rectangle. You could optimize this by only testing objects that are likely to be close.

There are many other ways of testing for collisions. Unless you are wanting to use some internal collision detection method most collision methods are independent of which graphics system you are using to display the objects.