What is the difference between total fertility rate and birth rate

The birth rate is the number of live births per 1,000 population in a period while the fertility rate is the average number of children born to childbearing women age between 15-44.

Explanation:

The average number of children that would be born to a women over her life span is termed as absolute/potential natality or simply the total fertility rate. There are two situations for such women first: if during her lifespan, she was to experience the exact current age-specific fertility rates (ASFRs). And second: if she was to live her reproductive life from birth to the end.

While the total number of live births per one thousand of population in a year or assigned time duration is understood as "birth rate". It is calculated from a population census, global registration system for births or by demographic techniques.