Many software packages, and specialty such equipment as routers, use their own access control. The majority of these have a default username and/or password set, to be able to set them up for your system.
Once these are setup, the default password needs to be removed. For example, if someone is scanning addresses, and finds your router, when they connect it will usually identify itself, telling that person what they have connected to. If the default password has not been removed, it is easy for that person to lookup what the default is for your router, and log into it. They could then change the settings, and take you offline. Even worse, they could possibly use the information they find in your router, to further infiltrate your network.
It seems like an obvious thing to change, or delete, the default account and/or password, but in fact the majority of users do not.
If you are not familiar with your router configuration or similar topics contact CCS Retail for help.