From Bioinformatics.Org Wiki
The study of interactions between the components of biological system is Stems Biology. The interactions studied can be of various types viz., Protein-Protein interactions, Protein-DNA interactions, DNA-DNA interactions and between other molecules in an organism. The mapping of protein-protein interactions is key to understanding biological processes, thereby deciphering a function. The study of interactions is collectively termed interactomics (Benning et al., 2004).
Systems Biology is of two types: