What type of software allows users to draw pictures shapes and other graphical images with various on-screen tools?

If you have Microsoft Word, you can:

-- use the WordArt feature to "fill" each letter with a picture, but it won't let you fill a letter with more than one picture.

-- draw several smaller geometric and/or freeform shapes that you arrange to form a larger letter (such as a D), and fill each shape with a picture.