:%s/src/dest/gc subsititute
:1, $ d delete
:/name ?name up->down down->up find
:wq! save &quit
dd | 3dd delete a or many line
yy | 3yy copy many line
y | yw copy one charater or one word
xx delete charater
dw delete word
db delete backword
d$ delete cursor to line end
p can paste the content just use d (dd, 3dd, dw, db...) to delete
u undo
