I often notice a ton a people don't know the difference or think they're both the same. That's completely false. Pitch Decks are dramatically different then a business plan. Pitch Decks are great for being a "commercial" for whatever project you're trying to raise funds for, but they almost always have massively incorrect info, incorrect and over blown ROI, comps that are ridiculous (if your project is $3 million, but has a similar story to a $90 million film, you don't use the $90 million film as a comp), and little to no financing info.
On the other hand, nearly 99% of all investors (projects over $200k), will always require a business plan. They don't require pitch decks. Why? Because a business plan goes into REAL detail and has REAL projections and comps, along with including an executive summary, REAL profit sharing, REAL budget, and much more.
Most pitch decks I've seen, while looking really great and flashy, contain little useful info to an investor. So know your audience. Pitching to a producer or a production company to do your project? Pitch decks are fine. But pitching to an actual investor? You need a business plan. Sure, you can get a template for a business plan online, but unless you know the proper numbers and info to input into that template, it's worthless.
So make sure you're investing in the right documents for the right audience. Pitch decks are not cheap. Neither are business plans. So if you can only afford one, then choose the one that will actually help get you funded. PPM's are a whole different ballgame and in if you're seeking big budget numbers, in most cases, they are required, but the costs of a ppm will shock most that look into it and is a conversation for another day.
You'll also need to make sure you have an accurately done budget first (fyi, most REAL budgets run anywhere from 25 to 60 pages, not 3 or 4). And creating a top sheet can't accurately be done without a full budget. To create an accurate budget, you'll also need a script breakdown/shooting schedule. Again, done by a professional.
So think hard on what you are doing and who you are sending these items to. Yes, this is a bit of a commercial as I'm one of the few that actually specializes in custom made film financing business plans (DM for rates), but it's also a freebie bit of advice to those new to the game.
Choose wisely.