Are Bonsai trees real trees or are they another type of plant?

What are Bonsai trees?

Many people think of tiny little Japanese trees cut and pruned to a miniature size but literally speaking Bonsai means 'plant in a tray' and while they are smaller than their wild counterparts they don't have to be a couple of inches tall; they can be grown in a pot in the garden and will be smaller than their wild counterparts.

Misconceptions about Bonsai trees.

Many people believe that training Bonsai trees is a cruel pastime because the cultivator starves the tree and cuts it to such an extent that it becomes unhealthy. Quite the reverse is usually true; while they are cut and pruned quite heavily to keep them to the size of the pot, they are usually transferred from pot to pot regularly and are fed and watered much more often than their wild cousins.
https://sowamerica.com/bonsai-trees/

Bonsai ("tray gardening", in Japanese) is the art of growing miniature trees and plants, kept small by being grown in a pot and by the use of skilled pruning, formed to create an aesthetic shape and the illusion of age, although many bonsai trees are quite old and simply show their age in miniature form. The Chinese art of penjing is very similar to and is the precursor of the Japanese art of bonsai.

https://en.wikipedia.org/wiki/Bonsai

I have heard that the French have a method of pruning these plants so that they are even all over. It is called Bonsoir which is translated as good smoothing (or something similar)

This site has over 250 hardy tree species; always good seed selections for Bonsai cultivation. So, there are a ton of different kinds of plants that you can Bonsai.

http://bonsaisite.com/seeds.html

The original bonsai were found in the wild, growing in cracks and crevices of rocks - just the way you find buddleias growing in garden walls. If I remember correctly, it was a hobby in China first of all to collect these and keep them small in pots. Later, the hobby spread to Japan, where the supply of naturally bonsaied trees began to run out, and totally domestic cultivation began. The domestic cultivator tried always to mimic the effects of wind and deprivation found in the wild bonsais, and this meant using wire to twist the trunks, and small rocks to lift the roots up. Natural bonsais can be found anywhere where there are trees to provide seed, and poor or limited growing conditions.