1. He walked up the street.
2. He walked down the street.
What is the difference between the two sentences if there is any difference at all?
Do 'up" and "down" mean "along" or something else?
Go straight up/down the street and you will see the shop on your left.
There's almost no difference if you're in a small town and the ground is flat.
If the streets are oriented north-south, you could go "down" a street if you are headed south, as you would if you were looking at a map. In New York City, you go "up" an avenue as you head north and and "down" as you head south.
If you are in a larger town or city that clearly has a "downtown" area, then usually you head "down" a street if you are heading toward the downtown area.
And obviously, if the street is on a hill, it would make the most sense to say "up" when it goes "up," regardless of which direction it goes!