what does this statment mean? [closed]

if [ $option -eq 2 -o $option -eq 1 ]

In this code first, the code is run with option 1, which simulates some sort of files. After that, the input is given for "option 2" so that other sorts of a file are read. This statement was used after option 1 is completed. I want to know what does this statement means? Thank you