If someone comments that you are very industrious, they are complimenting you for working hard and tirelessly. You can have the evening to yourself if you're industrious enough during the afternoon to get your homework and chores done.
The word industrious is closely related to the word industry, used for both the quality of being hardworking, “He is a model of industry,” as well as a field of business, "the construction industry." It might help to remember the Industrial Revolution, the time when machinery was introduced to the manufacturing world. If you're industrious, you work as hard as machines do!