A Dobsonian telescope is a Newtonian mirror telescope, which is suspended in a so-called rockerbox (wooden box), which replaces the mount and tripod. A Dobsonian telescope is therefore very simple, so that here the money is almost exclusively invested in the optics.
A Dobsonian can be easily moved in all directions. Additional roller bearings and pivot bearings facilitate handling. If you invest in a Dobsonian, you have the advantage of a quick set-up, because the telescope consists only of the OTA and a rockerbox. Both parts are assembled extremely quickly, and you can start observing without having to first align the telescope.
Dobsonian telescopes are particularly good for beginners who want to start with a large telescope for relatively little money. In many cases, the OTA can also later be easily mounted on an astronomical mount with a tripod.