PIC micro-controller vs Arduino

what is the different between PIC micro-controller vs Arduino ?

No one has said this yet, so I guess I will:

A "PIC microcontroller" is a chip (actually, a broad range of chips encompassing three different architectures and hundreds of different configurations.)

"Arduino" is a board-level hardware product and accompanying development environment. It plugs directly into a USB port on your computer, and allows you to start writing high-level language programs pretty much immediately

To get the "PIC Microcontroller" to be like an Arduino, you need a board that holds the chip and provides USB communications, and you need PC-side software including a compiler. These things do exist, at least for some subsets of the PIC microcontrollers. But a random PIC microcontroller chip by itself is pretty distant from an Arduino.

People have already mentioned the chipKit boards, which use an arduino-compatible IDE. They're swell; more powerful than Arudinos of similar cost, just as easy to use, and reasonably well supported. They don't have the community of the Arduino; they're a couple years behind. The USB bitwhacker is another example; it actually showed up at about the same time as the original USB Arduinos, but it didn't include development software (you had to use the stuff provided by Microchip.) There's also JALuino, which uses an alternative high-level languag ("JAL")

PICAXE I'd actually categorize a bit differently, since it's interpretted (slower) and is thus dependent on buying the chips (containing the PICAXE interpreter) from the PICAXE people. A big strength of the Arduino-like systems is that they operate on "bare-metal chips" with all open-source libraries. (That doesn't mean that they're not a useful product! Just somewhat different.)

Interesting comparison with the LED code...

I have to second westfw's stance here though. "PIC" is not equivalent to "Arduino". It's equivalent to "AVR". You can get a pretty small blink program to run when you're not hauling around the Arduino libs. If you're willing to write assembly, it can be very small indeed!

Another thing which I haven't looked into myself is the execution efficiency. AVRs run most operations in one clock cycle. (Obviously, data fetches may take longer.) Does that hold for the PICs? On a similar vein, 32-bit PICs will have a potential advantage at large number math, since the AVR would take multiple operations to do the same. Perhaps many more, depending on the operation.

Then there's the AVR32, which I don't know much about...

Clearly, comparing MCUs isn't exactly apples and oranges. :-)