what is the difference between monera and protista ?

Monera

The monera are the simplest of organisms, almost all microscopic. Each individual is just one prokaryotic cell—a cell that has no membrane bound nucleus or organelles; that is, there are no structures inside the cell. Some monera can produce their own food by photosynthesis (using energy from the sun to produce food) like plants do, but many cannot. Some have whip like flagella that allow them to move. Bacteria and blue-green bacteria belong to the monera.

Protista

Like the monera, protista are single-celled organisms; however, the major difference is the organization of the cell. Protista are eukaryotes: a eukaryotic cell has a membrane-bound nucleus and other organelles inside, separate from the rest of the cell contents. Most protista can move. Some produce their own food by photosynthesis; others must ingest other living things. Amoebae, some algae, diatoms and other organisms belong to the protista.