The browser saves the received cookie locally to the device. Cookies are simple, they contain at least one name-value pair and are under 4KB.
Can you assemble the most logical version of the name-value pair in this cookie?
Sweet! Cookies have a name, in this case username, and a value, in this case KevinMcAllister.
Wouldn't it be more logical to name the cookie username and give it the value KevinMcAllister?