import ij # Activate a window by the window name ij.IJ.selectWindow("image.tif") # Activate a window by the window index ij.IJ.selectWindow(2)In the first code example, the `selectWindow` function activates the window with the name "image.tif". In the second example, the function activates the window with the index number 2. Package Library: The `ij` package is a built-in package available in Fiji, which is a distribution of the widely-used image processing software ImageJ. The `ij` package contains a variety of functions and classes used for image processing and analysis in Fiji.