I assume you are an enthusiast, who wants to host simple websites for you and your friends. In this case it is alright to host the sites yourself at home or office cost effectively. You don't have to worry much about power outages (I know how the power outages affect the working in some areas of India, especially in summers).
But to host a commercial website for an overseas company, many factors come in to play. Reliability, Uptime, constant updates and regular server maintenance.
Commercial web hosting companies work professionally keeping their servers in controlled environment, having enough redundant servers, with uninterrupted power supply, 24x7 staff for maintaining the servers. The costs of using these services also become cheaper. You will be free of all the headaches at the same time get a good service.
You can maintain the website through the control panel for uploading, updating the webpages, leaving the server side maintenance to the professionals.