PDF is short for Portable Document Format, which can be translated from English as “Portable Document Format”. It was developed by Adobe Systems for use by US federal authorities as a tool for storing working documents. This is a universal cross-platform format, which is now standard for electronic documents. It serves to convert text files (including photographs or other images) into electronic documents without any loss. To read PDF files you need special programs - Adobe (Acrobat) Reader, PDF-Viewer and others.
JPEG is the most common and popular bitmap format. The form got its name from the name of the organization-developer Joint Photographic Experts Group. Files of this format are used today in all digital cameras and cameras. They have a good compression ratio and support 24-bit color depth. Since such compression significantly reduces image size with virtually no loss of quality, JPEG format is widespread on the Internet. However, the stronger the compression, the worse the quality. In addition, the JPEG format does not support the transparency option.