Answer:
client
Explanation:
The client makes a request for a service, and a server performs that service.
Opening unfamiler emails and visiting unknown websites
Nothing, it will just keep sending you annoying notifications that become more and more frequent, i would just confirm it if i were you
A .xlsx file tells you that the file is an Excel workbook that utilizes XML files to create the various spreadsheets as well as macros and other hidden codes used to perform certain functions (which is why there's an X at the end; older .xls files had no indication of this external code being present, which is why they're almost never recommended for modern use).
