In sales, your "pitch" is what you say to people to introduce your product or to get them to buy something. It's about 30 seconds to 5 minutes long. A salesperson's pitch is usually the same, or very similar, every time they talk to a customer. You can use the word "pitch" as a noun, like in the example at top. You can also use it as a verb:
Could I come to the next Directors' meeting and pitch my idea?
There are other kinds of "pitches" as well. For example, a writer might have to "pitch" an idea for an article to an editor. At a television studio, a TV show creator "pitches" the idea for the show to the television executives.