The modern International System of Units (SI) was originally created as a formalization of the MKS system, and although the SI has been redefined several times since then and is now based entirely on fundamental physical constants, it still closely approximates the original MKS system for most practical purposes.
The modern International System of Units (SI) was initially established as a formalization of the MKS system, and although the SI has been redefined multiple times since then and is now based solely on fundamental physical constants, it still closely resembles the original MKS system for most practical applications.