Whether a function is anonymous or not is sugar. The important thing is functions aren't special, they can be passed around (i.e. the are 1st class objects). I

Whether a function is anonymous or not is sugar. The important thing is functions aren't special, they can be passed around (i.e. the are 1st class objects). I actually can't fathom having to code in a language in which you can't pass functions around. Call backs is my biggest use of function passing. This is really, really huge. Currying, decorating/wrapping functions Replacing methods/functions at run time. Great for testing. Putting them in data structures. Often dictionaries. Often to create more dynamic switch like logic. dict[key] = func_that_handles_key, etc. then later, dict[key](key) Lots of data is code stuff. Closures just make the passed functions more powerful / convenient as they capture their scope. Which is often used (at least by me in Python) to create function factories that return custom functions. A contrived example but a pattern I use often. Logging object with warn, debug, error functions. You could hardcode / boilerplate each of those functions but that is boring, tedious, and nonDRY. So instead you create a function factory and use it to return anonymous functions, like so. Python. def log_func_factory(level): def closure(msg): print level, msg return closure class logging(object): debug = log_func_factory('debug') warn = log_func_factory('warn') error = log_func_factory('error') With real code I'd not repeat those assignments and instead use a loop driven by data. for level in ('debug', 'warn', 'error'): setattr(logger, level) = log_func_factory(level) Bam, data driven code. Very DRY, very concise, very dynamic. Maintenance is adding one text string in one place.