As the name suggests, thickening makes the hair fuller and stronger, but with the same final length as your own hair, whereas lengthening makes it longer.
Hair extension is a term for various methods to make the hair on the head appear stronger and longer by using strands of real or artificial hair. The English technical term is Hair Extensions. In Germany, this service is mainly offered by hairdressers due to regulations of the Chamber of Crafts. In some federal states, however, chambers of trade also grant "Exceptional permits limited to hair extensions" to persons outside the profession.
Since hair extensions are always attached to the hairline, each extension automatically results in a compression.
Hair Clip Extensions can also be applied by the customer without any problems. For bonding and tape extensions we advise against applying them yourself.