What is the difference between a closure and a lambda? And here comes the closure part: The closure of a lambda expression is this particular set of symbols defined in the outer context (environment) that give values to the free symbols in this expression, making them non-free anymore
Type hinting – Difference between `Closure` and `callable` Note for readers of this question and the answers herein: there are some references to Callback (upper case) This is incorrect It's just callback (lower case), which is a type hint It's not a class Conversely, Closure is an actual class that exists in the global namespace, and should therefore be capitalised
sql - What is a database closure? - Stack Overflow A database closure might refer to the closure of all of the database attributes According to the definitions above, this closure would be the set of all attributes of the database itself The closure (computer science) term that you linked to is not related to closure in databases but the mathematical closure is