SPD pedal:



SPD-SL pedal:



SPD pedals are double-sided "mountain bike" pedals with a small contact area that use two screws maybe 2-3 cm apart to hold the small metal cleat to the sole of the shoe. The SPD-SL pedals are single-sided "road bike" pedals with a larger contact area that use three screws in a triangle about 4-5 cm/side to hold the much larger cleat to the sole of the shoe.

The Shimano SH-R077 is listed as both SPD and SPD-SL compatible and since that's presumably a revised/later model of the SH-R076 that you're looking at, I'd assume the SH-R076 is also compatible with both.