The convergence of communication technology means the advancement of technology in a way that it's not limited by devices.
It stands for a process where a single device can perform a variety of services.
For example, a mobile phone can make calls, record audio/video, play music, connect to the internet, control appliances, track location and acts as a map too.
It also refers to the incorporation of traditional media sources into new ones. For example, newspaper and media houses launching their websites and applications so that news can be accessed from anywhere.