: This indicates that the file is the first part of a multi-part archive. Large files are often split into smaller segments (Part 1, Part 2, etc.) to make uploading and downloading more manageable.
Searching for "free" versions of these specific RAR files often leads to third-party sites that may bundle the content with malware, adware, or phishing links. It is generally safer to access content through official channels or verified digital storefronts like the Google Play Books