#12 grep is not working with pattern in single quotes

[Sai]

grep '<pattern>' file
is not printing the lines having the pattern from the
file.

Whereas by using
grep "<pattern>" file
is properly printing the lines having the pattern from
the file.

[Nobody/Anonymous]

Logged In: NO

You appear to be working in COMMAND.COM (rather than
sh.exe), which doesn't handle single quotes and passes them
to grep unchanged. That's why grep will search for
occurrences of '<pattern>', quotes included.