Tape extensions are pre-taped and then taped/glued together on either side of the natural hair. In most of the cases, a hairdresser would apply tape-ins for you because you need to align them to the roots. They are generally applied with a heated tool that heats up the glue. Additionally, you would need to have them removed (with glue remover) and then reinstalled. They can be re-used and if maintained properly, can be used for a long time.