Quick Share is a file sharing feature by Samsung. This feature is like AirDrop on the Apple ecosystem, except that it only supports between Galaxy phones or Galaxy tablets. If someone installs the software on a Windows laptop, file sharing between Samsung and Windows is also possible.
Nearby Share is the same feature by Google. This feature has been changed to Quick Share, using the same name as Samsung. On the Samsung Galaxy S24 series, Quick Share is no longer limited to Samsung devices but can also receive and send files to other Android devices.
According to Mishaal Rahman, Samsung is preparing to update other Samsung devices to combine Nearby Share and Quick Share into a single sharing feature. This is the best solution so that users don't get confused by having many sharing options in one device.
Now for the global market we have a combination of Samsung and Google, while Chinese devices such as Xiaomi, Oppo and vivo support cross-brand file transfer. Who knows one day, all brands of Android devices may also combine file sharing features into one.