Impression and page view means, when we are using internet and request to load single HTML file on the internet site while accessing Or you can say that, web page viewed by one person that is also used for online advertising.
Page Impressions are normally related to advertisements.
For example: You place one banners on your webpage and one person sees this banner 2 times. Therefore, this banner gets 4 impressions and Page Views are normally related to users and browsers. You may see you have larger page impressions than actual visits.