They combine the features of a mixer and a recorder with a microphone pre-amp. Fostex, Akai, Roland, Tascam, Korg and Yamaha make similar models. Since they record to a hard drive or a Jaz disk, no tape is needed. If you drop it, repairs can be very expensive. They frequently fail to record properly.
Good microphones are expensive.
This is very true if you go digital. AKG, Hafler, Electrovoice and Neumann are the best. Shure makes the cheapest line used by professionals. So to make a long story short, I decided to go analog. It sounds great, is easy to use, uses cassette tapes, works with a cigarette-lighter adapter or a camera flash battery pack, and best of all I can get it repaired in town.