how to search forprints all lines that match word1, word2, and, word3 in grep code example

Example: grep more than one word

Just use one of following forms with grep or egrep commands :)
grep "PATTERN1\|PATTERN2" FILE
grep -E "PATTERN1|PATTERN2" FILE
grep -e PATTERN1 -e PATTERN2 FILE
egrep "PATTERN1|PATTERN2" FILE