Hey Deep,

IT is for lan and wan machines administration in companies and other public organizations
ICT is like IT adding telecommunications like mobile, voip, gsm, gprs, 3g. and so on
Both are based on Computer Science but users and administrators side.

All the best!

Information Technology(IT) and Information and Communications Technology (ICT) are often used synonymously. However the key difference is that IT is a subset of ICT.

ICT covers all forms of computers, networks, information etc. that IT covers and it also has an extra focus on all forms of communication including telephony, mobiles, wireless networks, middleware (hardware and software), other enterprise softwares, audio visual systems that enable movement or manipulation of data.