what does it mean that apex is an on demand programming language? the text book says it's functionality that you need and is availbile in the cloud.... and that it's also plugged into platform features.
I'm afraid I don't really follow the definition.
On demand languages are entirely provided by a service provider, and so usually have minimal requirements to get started. For example, with client-side applications, you need a compiler or interpreter that has to run on each client, and have to find a way to install/distribute these components to other systems. Most server-side languages are either compiled locally and uploaded, or are scripted, meaning you have to debug them very manually. In contrast, on demand languages compile and run "in the cloud," are easily distributed, and usually requires no more software than what comes standard with most operating systems (e.g. a web browser).
Short answer is - it means that it's available if you need it, but you can still use the platform's functionality and features even without using apex.
I agree with SFDCFOX. but want to add some more points here. 'On Demand' means, you can use the tool at any places, irrespective of any machine. Whenever you want, it will be available.
