It’s a good question and one that is both simple and complex to answer.
In essence, an Indie Film is a production of a motion picture that is done outside of the major film studio ecosystem.
Confusion happens when you start to think Independent Film = Low Budget. Luc Besson, the director of The Fifth Element, made a MASSIVE indie film called Valerian. It tipped the scales at a whopping $180 Million Dollars. So, don’t think that independent film means cheap.
Indie films are a staple of the Film Festival circuit and where most people get their start. Take the 1994 Indie Clerks, by Kevin Smith (IMDB). Without this pivotal film in the View Askew Universe, Kevin Smith may not have found his success. Smith has gone on to make 38 feature length films since then.
The point of all of this is that trying to classify Indie Films into a single narrow point is impossible. They range from Ultra Short films to Feature Lengths, Documentaries, Fiction, Fantasy, Horror, everything.
What you need to know is that the Indie Film market is large, wide and varied. There’s tens of thousands of filmmakers putting out as many productions and there’s always something new to see.
The downside is that there’s also A LOT of derivative and just cliche productions out there because there are no gatekeepers. If you can raise enough money to make your film you can make it. Film critics (I use this term loosely) rag on Indie Films because there’s a pattern of conformity that a lot of indie producers make.
In conclusion, when you’re considering checking out some new material to watch consider the Indie Film. It may shock you to find out there’s a lot of big budget well produced stuff out there by some of your favorite producers.