Routers and firewalls can be confusing. They essentially serve the same purpose: getting the internet to devices on a network.

A router like you’d purchase for $100 at a big-box store is designed to serve the needs of home, not the needs of business. A great WiFi signal (so little Jimmy can play his Xbox game) is likely more important than being able to deny access to your network by North Korea.

Unlike a router, a firewall is intelligent. You typically pay a subscription fee because the firewall is constantly updating itself to protect against the newest cyberattacks. A firewall actually looks at all internet traffic attempting to pass through to make sure it’s legitimate, that it’s not a virus and that it was requested from an in-network device; a router does not.

Firewalls can also totally block access by third-world countries known for producing cyberattacks. And a good firewall can let you know what your staff has been up to, as in: Who’s that looking on careerbuilder.com for five hours?

Don’t cheap out, and don’t buy your business’s link to the internet at a big-box store. It truly is the gate between your business and the rest of the world. You want a strongly armed guard, not a non-intelligent robot. If you can afford to invest in one thing, get a good firewall.

P.S. — Business-grade firewalls can be used in homes, too, especially if you want to control the internet content users can access and if you want to see what the people in the house have been doing. There is no rule that a firewall is just for business; IT providers sell them for use in the homes of lots of CEOs, CIOs and other professionals.

Alan Edwards, CISM, is chief information officer at Computerware, Inc., in Vienna, Virginia.