When you see http://localhost/, or https://127.0.0.1/, it refers to network address of the computer you’re currently working on.
Localhost is a loopback address, associated with your computer’s local IP which defaults to 127.0.0.1 for IPv4, or ::1 for IPv6
You might also ping localhost, here hos it looks in my case:
ping localhost Pinging DESKTOP-HCJ9KLE [::1] with 32 bytes of data: Reply from ::1: time<1ms Reply from ::1: time<1ms Reply from ::1: time<1ms Reply from ::1: time<1ms Ping statistics for ::1: Packets: Sent = 4, Received = 4, Lost = 0 (0% loss), Approximate round trip times in milli-seconds: Minimum = 0ms, Maximum = 0ms, Average = 0ms
Please take note – my local IP is displayed as ::1, as my computer is connected to the network that has IPv6 addresses