What is the different of Arduino as ISP and AVRISP?

When I was getting started with Arduino I quickly found need for a programmer

From the number of posts regarding ISP and loading bootloaders, I think we can say that the "need" continues. I often recommend just building one using a clone UNO with a ZIP shield. The small investment will pay dividends over and over and over. I used an Adafruit ZIF shield for mine. The black lines on the ZIF outline the tiny85 area for programming.

ATmega Modified Adafruit Programmer by Rayburne, on Flickr