1) What is the difference between a zoom lens and a telephoto lens?
Zoom lens means you can change from standard focal length for example 3.6mm or 6mm ( for mini board lens or pinhole lens) or 35mm/50mm lens for mirrorless camera or DSLR camera like Sony/Nikon/Canon/Fujifilm etc change or extend more long objective focal length like above 12mm even 20mm ( board lens) , 100mm even 200mm ( for DSLR camera) etc. or do opposite from telephoto to wide wide angles ( small focal length).
Telephoto lens is only means its Focal length 12mm more ( for pinhole board lens)  or 85mm more( for digital cameras) 
zoom lens is a lens which can go from wide angle to telephoto range. Or from low telephoto range to high telephoto range, means from low value of focal length to a high value of focal length.  
But a telephoto lens is specially made for working in the telephoto range.

2)  gopro replacement lens


 the original lens of gopro hero camera 4/5/6 is damaged or destoryed or broken easily after many extreme outdoor actions,


 or its quality become down or unclear,  then you have to buy and change one new chinese similar lens to replace it


 why not buy original lens from gopro?  as its price is too high to accept,  the price and quality of ours are acceptable for you


 how to DIY replace one replacement lens for your gopro lens?


 you can view this perfect DIY video youtube.com



good luck!