employee communication?
 

What is the best way for employee communication in a corporate company I mean to all the employees not a single one.

There are many ways like speakers that are in all the rooms and you can hear what the boss is instructing you. And another method is employee communication through digital boards. by which you can show whatever you want to show your employee.

There is an app which can increase the communication between different specialists. Here is the description of it. Not sure that it's suitable for big companies but the interface and service itself are rather convenient.