Make it clear to me..

The GrabImage function is what you use to 'draw' to images, instead of buffers, correct?

Exactly as the docs say - grabs an image from the backbuffer.

Pixmaps is what you draw to. Whether you load one, or create one, or create one by grabbing the backbuffer, or you lock an image and it turns into one, you are working with the pixmap.

No.

How do you draw directly to images then?

You can only draw directly to pixmaps. You have to grab the image, or create a new pixmap, or load a pixmap, and then modify the pixmap. Then re-upload it as an image in order to draw it.

Why did they have to change it, it was so simple with imagebuffers :(.

So, can anyone give me an example or does it come with Blitz Max?

writepixel is used to draw directly to images.
To do the same with GrabImage you must...
cls
drawimage1
draw_other-stuff
grabimage

So Grabimage takes a part of the screen and copys it from x,y, imagewidth, imageheight and puts it onto the image?

Yep