Defining Mastery-Based Learning is complicated by the fact that educators not only use a wide variety of terms for the general approach, but the terms may or may not be used synonymously from place to place.
A few of the more common synonyms include competency-based, proficiency-based, outcome-based, and performance-based among others. Connecticut uses the term Mastery-Based Learning, but all these terms are effectively interchangeable.
The terms other states and organizations use describe the same educational system. Additionally, the term Student-Centered Learning is also used by some schools and districts to describe the work they are doing to rethink the traditional time-based delivery of curriculum and its corresponding cookie cutter approach.
For more about how mastery-based learning differs from traditional education, check out this comparison.