Pattern is simply a good common solution to a common problem in a common situation. They come from engineering disciplines - originally architecture, with extensive use in computer science. They are a sort of cheat sheets to help practitioners with ready common solutions for common problems. They are especially popular in disciplines where the complexity of the subject approaches the limits of human mind.
Like in Computer Science.
Like in marketing.
Often they are not the whole solution, but rather parts of it. If you follow them, you'll need other patterns, but if you don't follow them, you'll be in trouble. It's the recombination of patterns that makes a viable full-fledged solution. Fortunately, there are patterns for how to combine patterns. They are called integration patterns.
Here are a few examples of marketing patterns:
For every pattern I am trying to provide:
Anyway, just browse the site and read them. That will explain patterns better than a thousand words.