Background

A Background is a layer of tiles, mapped and possibly scrolled, that appears behind the sprite layer. The SNES supports up to four simultaneous backgrounds, conventionally named:

• BG1
• BG2
• BG3
• BG4

throughout the official Super Nintendo development manual.

Mode	# of Layers Displayed	Layer	# of Tile Dots	# of Tile Colors	# of Palettes	# of Colors Per Layer	Function
0	max 4	BG1	8x8	4	8	32
		BG2	or	4	8	32
		BG3	16x16	4	8	32
		BG4		4	8	32
1	max 3	BG1		16	8	128
		BG2		16	8	128
		BG3		4	8	32
2	max 2	BG1		16	8	128
		BG2		16	8	128
3	max 2	BG1		256	1	256
		BG2		16	8	128
4	max 2	BG1		256	1	256
		BG2		4	8	32
5	max 2	BG1		16	8	128
		BG2		4	8	32
6	1	BG1	16x8	16	8	128
7	1	BG1	8x8	256	1	256
EXT BG	1	BG1	8x8	128	1	128

Reference

• https://archive.org/details/SNESDevManual/book1/page/n199