There are so many ways to join two pieces of wood together. When I first started woodworking, I did the easiest joint I could make - the Butt Joint. This is simply butting two boards together using glue, nails and/or screws. Over time, my tools and skills improved, and I began to master various traditional joinery methods.
(1) Lap Joint
(2) Dado Joint
(3) Box Joint
(4) Mortise and Tenon Joint
(5) Mitered Rabbet Joint