if some lines are too long, it will be forced to be newlined.
for example, normally a long line will looks like this
1 first line
2 this is the long
No, if some lines are too long and you have set wrap on they will be shown on "two lines", so to say, but there won't be a newline character between them. If you turn off wrap with set nowrap you'll see the effect.
Normally, k
and j
move you up and down. If you want to navigate wrapped lines use gk
or gj
, or just as some like it, map it to for example, the cursor keys.
nmap gk
nmap gj