unique user
noun [ C, usually plural ]
ukus(also unique visitor) IT, INTERNET, MARKETING
someone who looks at a website one or more times in a particular period of time, and who can be recognized by the address of their computer. Counting the number of unique users of a website, rather than the total number of visits to the website is a way of measuring how popular it is:
Last year, site traffic increased by 92%, to 849,000 unique users.