Pro Tools is the industry standard for digital audio production, but if you wanna get with the pros, you've always had to pay. No longer! Now, there's a free version of the software targeted at beginners, and that rules.
Pro Tools First is totally free, and as far as I can tell, that's not because it's terrible and won't let you export at the end of your session or something lame like that. No, it appears what we've got here is a totally functional and useful digital audio workstation.
The software has all the functionality you need to record, edit, and mix your music. If you don't play an instrument or sing, there's a built in synthesiser loaded with loads of software instruments so that you can compose directly inside the software, or connect an external hardware controller to trigger notes. Once you're done laying down your tracks, there's a suite of effects, sound processors, and a couple of basic plug-ins to get you started. In the event that you need more plugins, you've got access to loads through the app's marketplace.
It's hard to see what the catch is. Obviously, this software is going to have lots of functionality limitations compared to the full Pro Tools suite. It's possible that Avid's hoping to make money off the plugin marketplace, where people will go to stock up on better editing powers. More likely than not, First is a play at roping in people when they're just starting out. There are plenty of free options for beginners out there these days, and if Pro Tools doesn't plant itself in people's minds early on, it risks losing paying customers later.