Open up the Settings app and find Safari in the left-hand list, and then scroll down the right side until you find the “Clear History and Website Data” button.
You’ll be prompted to verify that you really want to do this, and it will point out that this is also going to delete the history from other devices using your iCloud account to sync Safari.
Note:
Cookies: The little data chunks websites leave behind (usually with your permission) that allow the site’s provider to know which pages you’ve visited on its site and other information. Cookies are also where a site will store any log-in information you’ve elected to save when you click “Remember Me on This Computer.”
Cache: More properly referred to as the web cache, Cache is all the webpages you visit and most of the assets needed to build those webpages. As a rule, video and audio are not cached. Cache help pages that you’ve visited before load more quickly.
Browsing History: The links to the pages you’ve visited. Clicking on a link in your history loads a page from your web cache initially.