You can use Filters as a search tool for visitors to your public Events Website.
For example, your organization might regularly organize events based around different general subjects. Let's say you're a bank who organizes educational events for customers. Perhaps the different areas your events cover are, Investing, Foreign Currency, Real Estate, and Trusts. You could create a Filter Group called 'Topics' and a Filter for each topic. Then you could apply one of those Topics filters to each event you create.
Checking the box to the left of a Filter makes it available in your Event Setup page to apply to any of your events.
Then, click on the pencil icon to open up the Filter edit box. Check the ‘Make This Filter visible on public Events Page?’ option. This makes those filters to appear as dropdown search categories on your Events Website, as below. If your website visitors select those Filter dropdowns, only events you have applied those Filters to will display.