The 1st Dimension:

The first dimaension is in fact, a line! Well, let me expand further. If you were stood right on that line above in some unspecified spot because maybe you started walking, and you wanted to tell your bro where exactly you are on that line, the only coordinate you would need to describe your location is the Y coordinate! Lets say you took 5 steps down that line (5 pxls ig) then you'd tell ur friend you're at y:5 and thats all the information they would need to know to know exactly where you are. In this dimensional plane, theres no forward, backward or left or right; theres only up or down.

And you know, just for fun, feel free to grab me (thats in that box right there) at put me on that line to give yourself a little visual! (im making this stuff interactive to keep your attention and all that)