In psychological research methods, what is the difference between reliability and validity?

The reliability of a research method refers to the consistency of a measure being used, and the ability to replicate that method e.g. someone who weighed them self throughout the day, would expect to see a similar reading each time. The two types of reliability are internal and external. And the validity of a research method refers to whether or not it measures what it claims to measure e.g. a test of intelligence should measure intelligence, and there is also internal and external validity.