Now a days people don’t want to pay for the stock images. All are looking for a FREE option.
https://unsplash.com/ and https://pixabay.com/ sites are very useful and provides royalty FREE images without charging a single coin.
There are many images are available for different categories or industries. You can simply go to the site and search anything in their directory.
Also you can search for the FREE Illustrations, Vectors and Videos.