It's a legit question, but if you have to ask, then most likely OpenBSD is not for you. I don't say that out of some elitist or gatekeeping motive, rather I think most people who use it have a specific need for it, or feel strongly about the principles behind the OS, which are security first and secure-by-default.

Here's a breakdown of some technical differences between the two, but really if you want to explore alternatives to Linux or even Linux alternatives I highly recommend you do so, even OpenBSD, but I respectfully suggest you have a use case in mind first.

https://www.geeksforgeeks.org/difference-between-linux-and-o...

The security first/secure-by-default mindset in OpenBSD means the core distribution is very locked down. By that I mean there's very little in the base OS in terms of services. OpenBSD had a robust "ports" selection for things you may need to add.

My use case for OpenBSD was as a firewall, but it was eventually retired because it just couldn't keep up with my network speeds. It still is a secure unix server for things like radius authentication of wireless clients.