cint

ROOT's prompt root [0] is in fact CINT! It allows you to call functions, load files, etc. Lets look at the power of the prompt:

Running C++

You can simply type C++ code at the prompt: sin(0.1) will print the sin of 0.1, as one would expect. All ROOT classes and their functions are available, too, so you can use them at the prompt.

Purpose

Reflex stores and handles reflection information (types, members, etc). It is written in C++. Its reflection catalog can be queried by a small set of simple API classes. See the chapter Accessing Reflex Data.