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.
TIFF is a format that allows you to store raster graphics with tags. It was developed by Aldus Corporation in conjunction with Microsoft so that it can be used with PostScript. Aldus Corporation owns specifications. Subsequently, this company merged with Adobe Systems. It is she who now owns the copyright to these specifications. Typically, TIFF files (Tagged Image File Format) are with the extension .tiff or .tif. Aldus was specifically engaged in the development of the format in order to achieve the preservation of scanned images. The popularity of TIFF can be explained by the fact that it is preferred in order to store images that have a large color depth. The format is used to send faxes, scan, recognize texts. It is widely supported in the printing industry. TIFF was chosen as the main graphic format of the NeXTSTEP operating system. Then from this system TIFF support migrated to Mac OS X. At first, the format supported lossless compression. Then it was supplemented in order to support lossy compression in JPEG format. We emphasize that the maximum weight of a document, if stored in this form, is no more than 4 GB. To open a TIFF file larger than 2 GB, you must run Photoshop CS.