Many network devices, including wifi, are supported in Fedora through kernel modules. But Fedora only provides support for devices that use open source code. So some wifi devices which use non open source proprietary code do not have the driver modules included in a Fedora install.
In those cases, the kernel module drivers for devices needing proprietary code, pre-packaged support can sometimes be found at a third party repository such as RPMFusion. Otherwise, it may be necessary to get the source code for the driver from the device manufacturer and compile the kernel module yourself. It's not usually necessary to compile the entire kernel, just the module for it.