Portable Document Format (PDF) is an abbreviation for Portable Document Format. Links and buttons, form fields, music, video, and business logic can all be found in PDF documents. They can be signed electronically and accessed on any Windows computer.

Yes, You can know it by asking the who send it  or by:

• Acrobat Reader is required to view the PDF.
• Select a file.
• Choose Properties.
• Toggle over to the Description tab.
• Near the title and author, look for the creation date and time.

Read More: Why am I not able to join the Telegram channel?