Ditto @Astralbee. Let me just add:
"Solid line" means a line with no breaks. Like if you were drawing it with a pencil, you'd put the pencil down and draw without picking it up.
"Dotted line" means, as the name implies, a line made up of dots. To draw it you would make a dot with a pencil, move the pencil a little and make another dot, etc.
"Dashed line" means a line made up of short strokes with breaks in between. You would put the pencil down, draw a short distance, pick it up and move it just a little, then put it down and draw another short stroke, etc.
I don't think there is a generally-recognized names for patterns like #3. I'd say "a line with alternating dots and dashes". Admittedly a long and cumbersome phrase. If someone said a "dash-dotted line" like Astralbee suggests I might figure out what he meant, but as I say, I don't think that's an agreed-upon term that every English speaker would recognize.