ConvertMyFiles supports file conversion to both searchable PDF and image PDF. While some might argue that a searchable PDF is more useful and practical than an image PDF, they both have their purposes.
A PDF, how most people are familiar with the format, is a searchable Adobe® PDF. When working with this kind of PDF you can click hyperlinks, use bookmarks, highlight, annotate and, as the name suggests, search for content. This is because a searchable PDF encapsulates a complete description of the file including the text, fonts, graphics, etc.
The key difference between a searchable PDF and an image PDF is that the image PDF lacks the text layer associated with the file. An image PDF is essentially a photo of the page and therefore lacks any information in regards to the actual content of the page.
An image PDF is typically created when people scan a document on a physical scanner. That said, an image PDF does have the benefit of additional security because it is impossible to search the document using keywords and difficult to copy & paste the text.
As previously mentioned, it is impossible to search an image PDF because the text layer is missing. However, it is possible to rebuild this text layer through a process called OCR. OCR is ideal for image conversions where new information needs to be added to the output searchable file; information that was not originally present in the input image file.
In conclusion: the difference between a searchable PDF and an image PDF is just as the name implies – the ability to use Crtl-f!