What is Arduino vs what is Raspberry pi

Hi bill (bperrybap)

You are talking about functions such as pgm_read_word(), right? PROGMEM is not a necessary part of Arduino programming. It's included to facilitate shrinking the size of a program. On bigger machines, you don't need to do that. On an 8 bit Arduino, it's a good thing - you can cram more into the little bit of RAM the chip has.