are clones of Cherry MX switches, made by either Kailh or Greetech and branded "Razer".
Razer Green = clones of Cherry MX Blue, Razer Orange = clones of Cherry MX Brown and Razer Yellow = clones of Cherry MX Speed Silver.
The differences between Cherry MX, Kailh and Greetech switches are not huge, because they work the same way and some parts are even interchangeable.
The Razer-branded ones are found only in Razer keyboards, but very similar switches made by Kailh and Greetech respectively (Blue and Brown instead of Green and Orange) can be found in other manufacturers' keyboards. When you see Yellow switches that are not branded Razer then those are usually
linear with a weighting in-between Cherry MX Red and Black.
I do personally have very little respect for Razer, mainly because of Razer SoftMiner but also because of them consistently using extraordinary claims in marketing, which misleads people.
Romer-G were made by Omron (an old microswitch manufacturer) and are found only in keyboards from Logitech, but related switches (but not the same) are found in a couple keyboards from other brands.
Omron's switches are their own designs and have a different construction and feel from the Cherry MX switches and its clones.
I'd say that which type of switch to get (Cherry MX/Clone type or Omron) is up to personal preference.
The Romer-G switches I have tried did not provide much tactile feedback.
Of Cherry's switches (and clones) that you could find in mass-produced keyboards, only Blue and MX Clear are known to provide much tactile feedback. Blue are clicky, Clear are not. They feel very different.
However, if you would build your own keyboard, then there are now multiple options for tactile switches ... and more each day, it seems. Definitely a rabbit hole to fall through.