| Properties | Plasmid | Episome | Remarks |
| Molecular nature | DNA | DNA | Both of them are made up of deoxyribonucleic acid |
| Genetic material type | Extrachromosomal DNA | Extrachromosomal DNA | |
| Integration to chromosomal DNA | Most plasmids do not integrate | Can integrate | |
| Terminology | The term “Plasmid” was first used by Joshua Lederberg in 1952. | The term “Plasmid” was first used by Jacob and Wollman in 1958. |
