While there are many excellent guides explaining how the search console works; the primary intent of this post is two fold:

a. Explaining the way Google calculates impressions, clicks and other data points.

b. Help you to understand the difference that you typically get from a page level view & the summary view – Especially when the sum of page level data is more than summary data.

  1. If multiple pages show up for a keyword, either in site links (as given in the below image), directly as subpage, or as multiple pages then the impression for that keyword would show up on individual pages, however, only unique impressions are be aggregated.

    So in the above case, 1 impression for the keyword top youtube searches would be calculated for each page (main page, and three sitelinks). However, instead of 4 impressions, only 1 would show up in the aggregated view.However, in case of click it only show for the url which was clicked. 

    How does Google treat sub-sections in GSC?
    If you use a # sign to navigate a user to subpages, and if those pages show up as sitelinks, then those pages will show up in GSC.
  2. How Google defines country? Is it based on location of interest, or the actual location.
    It’s based on the actual location. We tried it by running some searches by gl=country_id flag. It’s based on the IP address.
  3. Does Google take top 10 or top 100 into account while showing the impressions?
    It will depending on the search results per page of the user. For instance, if the maximum number of search results displayed on the user’s browser is set to 10, then only impressions for those 10 pages would show up. In the below example, you can see a clear co-relation in the position and impressions for a one query.
    Position and Impression Co-relation