VST presets and programs

VST presets for instruments can be divided into 2 groups: ‘presets’ and ‘programs’. Can someone please explain what the difference between the 2 are? In the manual it says that the ‘presets’ contain settings for all loaded programs. What do they mean by loaded programs? Do they mean how many instances of a vst instrument i load up? The manual says the ‘programs’ contain settings for the 1st or selected instrument slot. I don’t understand what they mean by this. What is an instrument slot?

The only thing i know is that if i add a new vst intrument i can then choose a vst ‘preset’ or ‘program’. To me i don’t see any difference between the 2. If i load up a ‘preset’ then the vst instrument loads up a specific sound with its settings and when i load up a ‘program’ then the vst instrument also loads up a specific sound with its settings so i don’t get what the difference is.

A VST might have multiple slots: each MIDI channel (1-16) plays a different program. This is called multitimbral.
ALL programs form ONE preset: the complete setup of all programs of a VST.

With a monotimbral VST a program IS a preset IS a program…