Which types of files are considered non-searchable?

Non-searchable files are types of files that do not contain text that can be easily indexed and searched by digital tools. PDF files can often be non-searchable if they contain scanned images of text rather than actual text data. This is because scanned documents are essentially images and require Optical Character Recognition (OCR) to extract any readable text. Similarly, documents created in word processing applications may be non-searchable if they are saved in such a way that the text is not directly accessible or if they are in a proprietary format.

In contrast, JPEG and PNG files are typically images and, like PDFs, may also be non-searchable unless OCR technology is applied. However, text and CSV files are fundamentally searchable since they contain raw text data that can be indexed easily. Executable and batch files serve different purposes, mostly related to running software or scripts, and are not typically considered searchable document types.

The nature of file formats and how they store data plays a significant role in determining whether a file is searchable. Hence, the option that includes PDF and Docs highlights common situations where files are often encountered as non-searchable in specific contexts.