When an image is created it is automatically protected by copyright, the creator of the image is automatically the copyright holder of that work, unless the copyright is transferred under an employment agreement or the image rights are sold. This means that unless image creators specifically indicate that individuals are able to use their content only the image creator themselves has the exclusive rights to distribute, reproduce, create a derivative work (creating a ppt presentation or digitally editing the image), telecommunicate, or publish the image. This means that most images on the internet "belong" to individuals and companies and you need to ask permission when you use them OR use them by the terms and conditions the creator or company has expressed for use for the image.
Image licences or terms of use are a way that individuals or companies can provide express permission for anyone to use their images without the need for individuals to request permission. Some common types of licenses that provide individuals with the ability to use images without seeking permission are creative commons licences.
Students and Instructors often use images as part of creating course content and completing assignments, while there are instances for the purpose of education, research and private study where it may be fair to use a Copyright protected image without permission. All RRC Polytech staff, faculty, and students must follow copyright policy at RRC Polytech. Library and Academic Services encourages students and instructors to use images that permit educational use from an open image license such as a creative commons license or images that have terms of use, or terms and conditions, that permit educational use.