Clarification about Unique in the segmentation chart?

Hey there,

I am new in Amplitude and unique events in segmentation are not 100% clear for me.

Scenario:

Let’s say I have 4 articles with 4 different titles (A, B, C, D) and I want to count, how many unique people read a specific article a day. (How often an article is read a day in total, that would be total events.) I am tracking reading with an event, when the user is opening the article. Let’s say, it calls article_open.

So for my understanding: With the function Unique as soon as the event article_open is performed this day an user is not counted again this day. So if user X reading the article A and later the article B (on the same day). Is user X only counted for article A (since he performed the event already and can’t be counted once more) or is he also counted as a reader of article B this day, too (since user X didn’t perform “article_open” B?)

Thanks in advance. :)