Hi,
I'm spikey1010. been doig hair for about 20 years. I really did't get into extentions but, i'll share what i do know.
First, there is the glue on, which you glue the track on with hair glue.
Second, the sew on track, which you make cornrows on the client's hair, than sew the tracks onto the cornrows.
Third, there is the fusion hair extentions, which you take a small section of their hair, and fuse the end of it onto the small section of track hair. this allows the extetion to look more natural. it moves better.beautyful but, takes a long time to do. good money though!!!!
There are so many other ways of doing extentions. look them up on line. some of them will even show step by step instructions.
good luck, i hope this helps. SPIKEY1010