The arduino website goes into some of these questions, but not in great detail.

So, what is the difference if one were to purchase an Arduino board or make one yourself? What benefits does buying the board have compared to assembling one from various parts?

I've seen that you can purchase the actual microcontroller (ATmega328 or similar) with and without the Arduino bootloader, what does this mean?

How would you go about programming a board that has been assembled separately(presumably without any link with arduino, the bootloader etc)?

Are there benefits of programming an Arduino through an AVR versus USB connection? Is programming in this manner similar to how you program with the Arduino IDE?

Sorry for an entire post with only questions, but these are things that I have read but not seen elaborated on.

The arduino website goes into some of these questions, but not in great detail.

So, what is the difference if one were to purchase an Arduino board or make one yourself? What benefits does buying the board have compared to assembling one from various parts?

I've seen that you can purchase the actual microcontroller (ATmega328 or similar) with and without the Arduino bootloader, what does this mean?

How would you go about programming a board that has been assembled separately(presumably without any link with arduino, the bootloader etc)?

Are there benefits of programming an Arduino through an AVR versus USB connection? Is programming in this manner similar to how you program with the Arduino IDE?