What is zero trust security and why do companies use it?

Zero trust is a security approach that says 'never trust anything automatically — always check.' Instead of trusting everything on your company network, it checks who you are, what device you're using, and where you are every single time you access something. Companies use it because it stops hackers who sneak onto networks — they can't just move around freely like they used to.

Old security relied on a locked perimeter — if you were inside the network, you were trusted. Zero trust throws that out. It assumes everyone and everything is a threat until proven otherwise. Every access request is verified: the person's identity, their device, its security status, where they are, and whether the request looks normal.