When a computer connects to a wired or wireless network, it can become a target for any other device on that network. In simple terms, a firewall acts like a security guard and only allows authorized traffic in and out of your computer. Your operating system may have a built-in software firewall. In your home network, you should also have a firewall built into your router/wireless access point.
Do not disable any firewall features without consulting with a trusted technical resource. Cyber criminals will attempt to disable security solutions to allow them to take control of or infect your device.
Most suppliers of endpoint security (formerly referred to as anti-virus) programs also supply personal firewall programs. MSU Denver uses advanced end-point security software that acts as an anti-virus and a firewall. We also use hardware based firewalls for our network.
See also
https://us-cert.cisa.gov/ncas/tips/ST15-002