When you are building a website or need a specific image, it is possible to source the image online. However it is not always legal to take an image that you find online and simply use it as your own, as copyrights may apply to the image. However there are a number of free stock photo sites where you can source and use thousands of free images completely legally. In some cases you might have to register for the site but they do not take any payment details from you and are considered safe sources for material.
Free Stock Photo Sites
Wikimedia is partly powered by Wikipedia and has a database of over 16,500,000 media files that you are able to use, including photos, videos and sounds. The user interface and categories can make finding what you are looking for a bit difficult but there are millions of photos to choose from and if you search hard enough you can locate photos of most subjects..
Flickr contains photos from both professional and amateur photographers and you need to be careful when taking photographs off it in making sure that you are legally allowed to use them. An easy way to keep yourself legal and access only legal-to-use content is to use the “Advanced Search” option and click on “Only search within Creative Commons-licensed content“ at the base of the tab. Any photos you find in the search you are free to use in presentations.
EveryStockPhoto is essentially a search engine for free-to-use photos. It finds the images at a variety of different sources, to which it provides a direct link. All photos it links to can be used in your presentations.
Stock Vault gives you access to a selection of over 38,000 free images. You are required to register to be able to download photos but once you have done so, you can search via keyword or category and find high quality images to use in your work.
Stock Xchng is similar to Stock Vault, requiring registration to gain access to a database of thousands of images. A quick not for you when you are browsing. Be careful to check the license under each photo, to ensure that the artist allows its use in your presentations.