If you need help and someone tells you to go to some place, they will most likely give you two sets of numbers i.e. 31, 59 these are coordinates and indicate the position of someplace within a map.
They correspond to the grid location, each map is a 100 * 100 grid so 31, 59 would mean the 31st column, and the 59th row. They are also called x and y coordinates also with x being the first number (31) and y the second (59).
Travelling with coordinates
You should see an X and a Y box below the map on the left of the screen, together with a Go button. You can type the coordinates you wish to go to on the current map into these boxes and use the Go button to travel there.
Coordinates only apply to the map when you are outside of a town/building, so if someone gives you coordinates and you are inside a building remember to click the EXIT button at the bottom of the screen to exit the building first.