Use | to separate multiple patterns for the OR condition.
Example: grep 'pattern1|pattern2' filename
Use the -E option to send multiple patterns for the OR condition.
Example: grep -E 'pattern1|pattern2' filename
Using a single -e matches only one pattern, but using multiple -e option matches more than one pattern.
Example: grep -e pattern1 -e pattern2 filename
grep -v can simulate the NOT operation.
There is no AND operator in grep, but you can brute-force simulate AND by using the -E option.
Example : grep -E 'pattern1.*pattern2|pattern2.*pattern1' filename
The above example will match all the lines that contain both pattern1 and pattern2 in either order.)