Puppy is designed to run from a USB pen drive or from DVD. It is not designed to be installed to the hard drive although it can be.
The approach taken by Puppy is about minimalism where functionality trumps pretty graphics.
All the usual favourites can be installed including FireFox and VLC but there are a host of lightweight alternatives installed by default.
Puppy isn’t really an operating system therefore that I would advise inexperienced users to use as their main operating system but I can’t stress enough that you should give it a go by running it from a USB drive.
You can have great fun playing around with Puppy Linux and if you always carry a USB drive with you then you have a bootable version of Linux available wherever you go.