And in the header of the packets that make up our data is the address of our device, the MAC address (along with IP and a bunch of other information).
Whatever information leaves our device is in our control. Just because we cannot change the MAC address built into our NIC doesn’t mean we can’t make other devices think that our MAC addresses is something different. However, almost all popular platform such as Windows or OS X or Linux (and hence Android) support changing MAC addresses and pretty easily too. Each NIC is assigned a unique hard-coded MAC addresses that cannot be changed. All devices capable of networking (smartphones, laptops, routers) have one of these. The device that you’re looking at right now has a network interface controller (NIC), the thing that’s responsible for allowing you to connect to a network, like the internet. Read this one first to you fully understand how MAC addresses work.
