Hair extensions, also called hair weaves, are lengths of real or synthetic hair that are closely attached to a person’s scalp, adding length and/or thickness to the person’s own natural hair. There are several different systems for attaching hair extensions, some of which are longer lasting than others. When well matched in color and texture, and professionally applied by a competent stylist, hair extensions are designed to mix in and move naturally with a person’s own hair, making it difficult to tell the person is wearing them. They can provide volume, extend hair, and add highlights or lowlights. With the proper maintenance, some extensions can last up to a full year before they need to be removed.Types of ExtensionsBoth human and synthetic hair extensions are available, and both come in a variety of colors, textures, styles, and lengths. Each type has its own set of advantages and disadvantages. Natural or human hair extensions are usually significantly more expensive than their synthetic counterparts, though they are typically considered to be of higher quality. Synthetic hair is made from chemically processed fibers; although more affordable, it may not look as real and can be more difficult to style.Source: Wisegeek