Ethical investments are investments that have a positive impact on the world, while still aiming to grow your money as much as possible over time (the best of both worlds).
This usually means investing in companies that help to reduce climate change (such as green energy companies), and avoiding companies that don't have a good record of treating employees well and bad business ethics.
Investing can also mean lending money to governments around the world in exchange for interest (bonds), and ethical investments only select the very best countries to lend money to, with high ethical ratings.
Ethical investments can also be called ESG (environmental, social and corporate governance (company management)), or sustainable investing.