An SPF record stands for Sender Policy Framework record.
It's used to indicate to mail exchanges which hosts are authorized to send mail for a domain.
Major Difference of having SPF Record and Not having SPF record is when an Organization has SPF record then any fake mail sent using that company address will go to SPAM else it will go to INBOX. For Example :
Company A ( Has SPF Record) Attacker ( Uses A's domain) ----(Send to Victim)---> Victim's Spam mailbox
Company B ( Does not have SPF Record) Attacker( Uses b's domain) ----(Send to victim)---> Victim's Inbox mailbox
To Test if the domain has SPF record or not use following links: