The word prokaryotic actually means before the nuclues. So, in a prokaryotic cell it does not have a nucleus. It does, however, have a nucleiod. A nucleiod contains a long DNA strand, but it is not a nucleus. Prokaryotic cells are unicellular and generally live in colonies or alone. Bacteria is an example of a prokaryotic cell.
The word eukaryotic means having a true nucleus. Any organism with more than one cell, is made up of eukaryotic cells. A true nucleus contains chromosomes, which is the genectic information of the cell. A eukaryotic cell is more complex and larger than a prokaryotic cell. Plants and animals are examples of eukaryotic cells.