Before learning about AWK’s logical AND operator I used to string a pair of grep commands together to find two search terms:

grep abc filename | grep def

to find lines with both abc and def. This can be shortened into a single AWK command:

awk '/abc/&&/def/' filename

A logical OR is also provided using a pair of pipes ||

awk '/abc/||/def/' filename

You can also use the equivalent egrep command:

egrep 'abc|def' filename

To get comfortable with AWK, try using it instead of grep for a week. AWK has many more features than just printing fields from a file.