Search engine optimization is the process of fine-tuning a website to achieve optimal search results. It involves ongoing efforts like resubmitting key pages every few months and submitting new pages. There are two main types of search engines: crawler-based engines that use spiders to index websites and human-powered directories. Crawler-based engines rank pages based on where keywords appear on pages and how frequently they appear. Meta tags and page content can help influence how search engines index and rank pages.