Cloud computing is a computing resource where you can access hardware, platform,software applications, infrastructure as services against a charge/subscription on a 24/7 basis. In a layman terms, like we use electricity, gas, water etc, computing services are offered in a similar way which is termed as cloud computing. Cloud consists of the computing services.
Suppose you want to read some text which requires a particular software which you may need to install or buy. So instead of buying or installing, you can use a cloud computing service which has that software. It may charge you anominal fee.