What is strain?

In materials science, 'strain' refers to the deformation of a solid material resulting from stress. It is expressed as the change in length relative to the original length and is a dimensionless quantity. In biology, a 'strain' refers to a genetic variant or subtype of a microorganism (e.g., a virus, bacterium, or fungus). Strains often exhibit distinct characteristics compared to other variants of the same species. In materials science, strain is crucial for understanding a material's behavior under load. In biology, studying strains is essential for tracking disease outbreaks, developing vaccines, and understanding microbial evolution.