Google's free tool for site owners: how often a site appeared in Google's search results, for which searches, and how often it was clicked.
Search Console is Google's free service for people who run a website. Its Performance report gives clicks, impressions, click-through rate and average position for your site in Google's search results, by query, page, country, device and date. An impression there is a time your site appeared in the results, whether or not anyone scrolled to it.
For a brand, the queries table is a second way to count searches for your name. Filter to queries containing “code” or “voucher” and you see how often your site appeared for those searches, which on your own name comes close to how often they were made. A branded queries filter, where it's offered, splits queries with your name from those without; Google says some may be put in the wrong group.
Know three things before comparing it with anything else. It leaves anonymised queries out of the table, and once a query filter is applied they drop out of the totals too. Its dates are in Pacific Time, except the 24-hour view, which uses your browser's local time. And it counts your own site's appearances, so who else advertised on those searches is in neither it nor your search terms report. Keyword Planner gives Google's own estimate of the searches.
Google's own help and policy pages first.