This is a pretty common question because there are so many varieties of the same herb that tend to be available. The simple difference is that the "whole herb", "full spectrum", or whatever term a company may use is essentially the chopped up plant put in the pill... it's just the whole, unadulterated herb (or whatever part of the herb is listed on the label such as root, leaves, etc).

A standardized extract is generally considered a step up from the whole herb, as it has a higher concentration of one or two nutrients that exist in the herb's natural, raw state. It’s like comparing an orange to a Vitamin C pill in some ways, as an orange has Vitamin C in it, but the pill is an exact amount of the single nutrient Vitamin C.

A concentrate is kind of half way between those two options, as it is a higher potency than the whole herb, but it’s not set to an exact level of any active nutrient. It’s like comparing the orange juice concentrate in the freezer aisle of the grocery store compared to the regular orange juice in the refrigerated section; they’re both orange juice, but the one in the freezer is more concentrated so it fits in a smaller container (which in pill form would amount to a larger dose offered in a smaller pill).