InputNotebook

gives the current notebook into which keyboard input in the front end will be directed.

The current input notebook is the notebook to which textual commands in the front end are normally directed.

A palette window can be a currently selected notebook but cannot normally be an input notebook.

Give the notebook object for the current input notebook:

Perform additional operations:

Give the notebook object for the current input notebook:

Out[1]=

Perform additional operations:

Out[2]=

The notebook that starts an evaluation might not be the input notebook:

Both programmed operations and user interactions can change which notebook is taking input: