There are two main types of cells among living organisms:
Eukaryotic cell (plants, animals, fungi) which is more compound, conntains nucleus with genetic material in it, membrane-bound organelles (mitochondria, Golgi apparatus, lysosomes etc). Because of their complex structure, the process within such cells are often more comlex then those in prokaryotes. Eukaryotic organisms are usually multicellular
Prokaryotic cell is simple cell found in Archea and Bacteria kingdom. It doesn't have nucleus neither membrane-bound organelles. Genetic material of these cell is located within the cytoplasm together with proteins and metabolites. First living cell was prokaryotic cell. Organisms that are prokaryotic are usually unicellular.
Prokaryotes are usually smaller than eukaryotes. They also don’t have a nucleus so DNA is in the cytoplasm. They also have no organelle membranes where as eukaryotes do. Domains of prokaryotes include Bacteria and Archaea, and all eukaryotes are in the domain Eukarya. Both can be free living, but only eukaryotes can be multicellular. Prokaryotes first appeared on earth about 3.5 billions then eukaryotes appeared about a billion years later. Etc....
