Community Fibre is one of only a few companies in London that offers you a fast fibre-optic cable right into your home.
There are many companies that will try to sell you "fibre-optic" broadband but the fibre optic cable only goes as far as the green cabinet in your street or perhaps to the basement of your building. From there the signal travels along old copper cables which slows your connection down.
Next time you speak to your Internet Service provider ask them if their fibre-optic cable will come right into your home and see what they say.
This video explains a bit more about the benefits of having a Fibre To The Home (FTTH) connection like the one provided by Community Fibre: