In a way the salsa and pico de gallo are the same salsa and they both typically use the same ingredients to make the salsa and pico de gallo.
However salsa is usually thinner in consistency while the pico de gallo is thicker and chunkier than the salsa.
They are both Salsa though and usually taste the same or at least taste almost the same and other than the thickness and chunkiness of one of the other I cannot really tell much difference between the salsa and pico de gallo.
The Pico De Gallo however has the chopped up ingredients such as the peppers, tomatoes etc chunky and big enough to be really visible.
While the ingredients in the Salsa are chopped up smaller so they are less visible.