In Charts, 'Map questions' shows all responses in a neat chart.
In Map responses, the amount of responses is shown next to each question.
If you apply a filter to the question, the number will change to show the number of responses that meet that condition out of the full number of responses.
In Explore, you can zoom in on clusters of responses and see how many responses where placed in that area (Map Responses). The example pictured below shows 65 points visible (out of a total of 5765 responses) on the screen.
The tab next to it (Respondents) shows how many individual respondents made these responses we see on the map. This way you can easily check if they were left by multiple respondents or just one 'spammer', and find if there are similarities between pop-up question answers. In the example pictured below, the 65 points were placed by 48 individual respondents.