In ed and ex , a command affects only the "current" line - the first line of the file to begin with, and later the site of the last edit or movement command - unless you precede the command with an address to indicate some other line or lines. In sed , most commands apply to every line unless you give an address.
Most line editors address lines in three ways:
It's possible to address single lines or a range of lines.
describes the addresses you can use with ex .
If the address specifies a range of lines, the format is:
where x and y are the first and last addressed lines. x must precede y in the file.