It's very important. No successful business can operate on a daily basis unless all lines of communication are open, including employee to employee and from a boss to an employer. If proper communication is not present, productivity and quality of work will inevitably suffer.
Communication means exchange of views, ideas and words between the two parties, communication is very essential because all people are social animals and can't live in isolation, and in modern offices even in normal offices too like government (private sector and public sector) the proper communication is very essential, and useful, because the employees coordination is the result of better communication which leads to better productivity for the organization. There are many tools of communication like computers, telephone etc.