Bacteria are creatures with only one cell. This implies that each bacteria consists of only one cell.
This is in stark contrast to humans, who have billions of cells in their bodies. Bacterial cells are a fraction of the size of human cells. Bacterial cells can range in length from 1 to 10 micrometers.
Bacteria are prokaryotes, which implies they lack many of the eukaryotic cell organelles. They do, however, contain organelles and structures such as Plasma membrane and Ribosomes.