Traditional furniture makers will use the wood itself to form the joint. High tech methods are at the opposite end of the scale and they require expensive machinery and glues. Factories lend themselves to the high tech joints because they can achieve mass production this way. Individual joiners are more likely to use traditional methods because they are strong, reliable and have been used for thousands of years..
Butt joints are probably the simplest type of joint because they just require two bits of wood to be butted up against each other and then fixed with nails, screws, dowels or glue. This is also the weakest type of joint though so shouldn't be used for anything that needs to support any significant load.
The most simple joint that requires cutting is the miter. It is really an angled butt joint with the two bits of wood that come together being cut at 45 degrees to create a 90 degree angle. It is fixed using glue.
Dovetail joints are perhaps the most well known of any joint. Many cabinet makers use it as the joint of choice. You will recognise it because it looks like the tail of a dove and it is often found where two pieces of wood need joining at right angles. The join doesn't need glue because the joiner must cut two perfectly locking shapes that will hold together and give strength to the furniture.
The mortise and tenon joint dates back thousands of years and is used by woodworkers worldwide. It has plenty of surface area that can be used for glue and it can be used almost invisibly if desired. The mortise part of the joint is the square or rectangular hole and the tenon is the wood projection that slots into the hole. It often has shoulders that sit flush to the edges of the mortise when the tenon fully enters the mortise hole.
Tongue and groove joints are common in wood panelling, for example on wardrobe fronts. It is also commonly used on flooring. The two bits of wood are cut so that they slide together. The tongue is the projection of wood that slots into the deep ridge known as the groove
Now that you know a bit more about joints, you will be able to recognise the basic different types in the furniture you see in stores.