There's actually two things this means. The artist gets a very flat piece of fine grained wood of whatever size they desire, and then cuts a design, pattern or work of art into the surface, leaving the flat surface alone. This is then used as a block which is inked and paper is pressed against it, creating a print. So the meaning can be either the block itself or the print made from it. In essence, the flat surface is the inked part, but many things can be done with texturing, lining, edge fall of and the like. It's actually a form of engraving as with printing money, only in wood.
Albrecht Durer was the master of woodcuts.
What is the main topic in each of the two woodcuts
To print pictures.
Frederick Sandys has written: 'Reproductions of woodcuts by F. Sandys, 1860-1866' 'Reproductions of woodcuts by F. Sandys'
Woodcuts
Woodcuts and lithographs.
Escher
There have been hundreds of German artists who have paintd and made woodcuts. Let me guess that you want Albrecht Dürer, 1471-1528.
Woodcuts, lithographs, and mezzotints.
He used woodcuts, lithographs, and mezzotints.
Xylography - art of making woodcuts of an early kind.
print images on paper.