Forge welding represents the most basic way of joining metals together. It involves heating the workpiece to a high temperature, then applying pressure to it as it's being welded. The heated metal flows around the workpiece, forming a joint that is stronger than either piece alone would be
Forge welding is one of the oldest methods for joining metals together and can be used for practically any type of material. It's especially well suited for larger items like machinery or vehicles, but it's also used for smaller projects like jewelry and costume accessories
There are literally hundreds of different types of forge welding techniques that are all over the place, but if you're going to learn about metal flow forges you need to start with understanding exactly what a forge is and what metal flow forges can be used for.
types of forging with respect to metal flow