We'll start with some of the most simple and basic patterns you can create: patterns that match specific sequences of characters, patterns that match only at specific places in a string, or combining patterns using what's called alternation.
One of the simplest patterns is just a sequence of characters you want to match, like this:
/foo/ /this or that/ / / /Laura/ /patterns that match specific sequences/
All these patterns will match if the data contains those characters in that order. All the characters must match, including spaces. The word or in the second pattern doesn't have any special significance (it's not a logical or); that pattern will only match if the data contains the string this or that somewhere ...