Robocalls and robotexts are pre-recorded messages that are delivered by autodialer software to your phone. Some may be from a legitimate company or organization you have a relationship with. Others may come illegally from scammers or telemarketers.  Read the FCC guide on how to stop unwanted robocalls and texts to learn:
Tips for reducing the number of robocalls and robotexts you receive
How to protect yourself from identity theft when scammers contact you