You will need a computer, Audio interface, monitors or headphones and your guitar.
Neural DSP plugins are full guitar rigs, that include pedals, amp(s) and guitar cab with mics (Impulse responses). Every Neural DSP product have different amps, cabs and pedals. Archetype products are made with collaboration with the artist (Plini, Nolly and Abasi) and have variety of amps from clean to High Gain. Archetype Nolly has four amps and four cabs. Archetype Plini and Abasi have three amps and one cab. All of the Archetype products have compressor, OD, delay and reverb pedals, but like said they are different in each product.
Standalone version can be run without a need of any other software. All you need is audio interface where you connect your guitar.
Plugin version is used if you wanna record your guitar with DAW. Otherwise it has the same functions as standalone version.
You get both versions when you buy the product and installer installs them automatically for you, if you don’t change the installation settings yourself.
Hope this helps.