Filedot is a file-hosting service. The "Preview" feature refers to the thumbnail or low-resolution image displayed on the download page before a user commits to downloading the full file (usually an image, video, or document).
If you meant (with a 'c') or "File .dot" (Microsoft Word templates): filedot preview
Disclaimer: File hosting sites often host user-generated content. Ensure you have adequate antivirus protection active when downloading files from third-party hosting services. Filedot is a file-hosting service