Masonry is when you take a variety of components and assemble them into a structure using an adhesive mortar. This is done by stacking one piece on top of another, with some sort of bonding agent in between them. The materials used can be just about anything, but it is usually some kind of stone. The materials can also have almost any shape, although those with linear lines tend to create the most stable structures.
Masonry generally creates buildings which are very strong, although their vertical power is much greater than their horizontal strength. This is because the various components that go into its structure are layered, one on top of another. This means that each piece is supported both from above and from below. On the left and on the right of the wall however, there are no stones supporting it, making it susceptible to twisting and shaking forces, such as those you get during an earthquake.
The final appearance of a masonry wall is determined by the type of materials used, and the way that they are patterned. You can use standard bricks set in a slightly offset pattern, this was very common in America in the seventies. If this is too uniform for you, you can try throwing in a few discolored bricks. Many designers add a charred or reclaimed brick to a standard pattern to create a unique look.
If you want to get even crazier, there are a variety of natural stones you can also use to create your wall. You have marble, slate, travertine, limestone, sandstone, quartzite, and granite to select from. These stones can have uniform colors in a variety of shades, or can be multicolored where each brick is a different hue. When using exotic stones it is important to understand their resistance to weathering in your geographical location, or they may start to fall apart after a few years.
Occasionally veneers are used to simulate the look of a masonry job. Veneers consist of thin stones or faux stone materials, which are designed to look like the stone components in a standard masonry installation. The individual parts of a veneer are usually extremely thin in order to conserve the space which is taken up by the thickness of the wall.
Masonry is an ancient profession, and the tolerances and properties of such projects have been well documented over the years. Those who practice this artistic profession often receive their training through an apprenticeship of 2-3 years. Others can be trained through various school and university programs which combine theory with practice.