A method of parameter estimation by equating sample and population moments then solving the equations for the unknown parameters.
Method of Moments estimation (MoM or MME) is an approach to parameter estimation which equates sample and population moments to solve for unknown parameters.
Loosely, the Law of Large Numbers suggests that in as sample sizes become sufficiently large, the sample moments will approach the corresponding population moments; this is sometimes used to justify the MoM as a general approach.
While less commonly used than maximum likelihood estimation (MLE) – for example, it is quite often less efficient – it can be quite useful in many situations.