Making beats and working with samples has been made a lot easier with the introduction of the MPC from AKAI and the concept has been adapted for computer based workstations with their MPD rage. We will talk about the difference between them and help you decide which one is best for you.
A music production controller MPC is hardware used to make music. The company who makes the MPC units is AKAI and there have been several models. The MPC contains square pads to allow you to play notes. An MPC also has software built in to manipulate the sounds using knobs on the unit. An MPC is often used to make groove based music like R&B.
As the use of computer based music production has become common place AKAI have introduced a range of MIDI controllers called MPD. The MPD units do not have any software built in and act as a controller for computer based software. You can use a MPD to make beats the same as an MPC but you will require a computer DAW to store the sound and the editing functions are also performed on the computer.
So to conclude we can easily see that an MPC is for making music without the use of a computer and will store your sounds and let you edit and working with them while a MPD will require a computer to store and edit your sounds.
This is debatable and many MPC fanatics live by their MPC. In my opinion for a modern home studio an MPD works best if you are working on a computer based system and only using it to enter beats while a MPC works best if you want to do it all on the hardware and send the completed edit to a computer for mixing.