three practices of BDD

1.Acceptance Test Driven Planning
Acceptance Test Driven Planning is one of the three practices of BDD.5 It
is an extension of Acceptance Test Driven Development, which involves
collaborating with stakeholders on acceptance tests before we write any
code.6
The difference between the two is simple. ATDD specifies that we write
acceptance tests before we write code, but it doesn’t otherwise specify
when in the process we should write them.
ATDP specifies that the acceptance tests are agreed on during or possi-
bly before, but no later than, an iteration planning meeting. This lets us
consider the acceptance criteria in our estimates, which improves our
ability to plan iterations, hence the the name Acceptance Test Driven
Planning.

2.Domain Driven Design
3.Test Driven Development