Flower is the most full-spectrum as far as the compounds that may/may not have effects that come about only when in the presence of other compounds. Hash is an extraction which contains some of those compounds, but not all. Hash is made up of trichomes that are separated from the flower. Trichomes contain most of the good stuff that we go after. But there is a definite difference between smoking flower and dabbing a concentrate like hash. Typically, the hash high has a quicker onset, but a shorter duration. It usually takes a few pulls of smoke to get high from flower, but the high lasts longer and has a slower come up, peak and then a slower come down. If you're used to smoking joints and then try a dab of good hash for the first time, you might be startled by how fast the high comes on and peaks. That difference in onset is what sometimes makes people think that hash is a lot stronger than flower. And there are some types of hash that are different from one another. Like, back in the day, we used to get this soft, black Afghan hash that had a lot of plant material in it. That stuff would give the heaviest high and also last for hours! Bubble hash is a much more modern and pure form of trichome extraction that has very little plant material in it. My deduction is that there is some other "stuff" in the plant material that adds to the high not only in a qualitative way, but also adds a longer duration to the high. I can't prove that in any kind of scientific way, but that's been my experience.