Bacterial transformation refers to the absorption of DNA molecules from the extracellular environment through the cell wall, followed by integration of the molecules into the recipient genome or replication as an independent plasmid.

There are two types of bacterial transformation: 

1. Natural bacterial transformationrefers to the innate or natural ability of bacteria to directly incorporate DNA from the extracellular environment. 
2. Artificial bacterial transformation: refers to laboratory techniques such as heat shock treatment, electroporation, or the use of certain chemicals to develop competence of the host cell.