Get free pictures even for commercial use.
If you need pictures or even videos for your website or whatever it can be quite a costy thing.
So here are 3 sources of free images. Mainly also for commercial use:
https://www.pexels.com/
http://freeforcommercialuse.net/
https://pixabay.com/
Please note, that I am not the owner of the websites. Note also that the websites can change their policy or purpose. So always check by yourself as well. I am not responsible for any harm of use.