The Telephone is probably the most important invention made by Alexander Graham Bell Because of the fact that 6.8 billion people use phones now. And it is used at schools,Jobs,Home,Hospitals etc. It has been improved on for years. Because it is the fastest way to communicate with each other.
There are many careers who are based on Alexanders invention like Verizon, T-mobile, Samsung, Sprint, AT&T,Android,Apple, Etc.