What is what does it mean when it says sent as text message?

When a message is "sent as a text message," it means the message was delivered using the Short Message Service (SMS) or, less commonly, the Multimedia Messaging Service (MMS) protocol, rather than an internet-based messaging service like iMessage, WhatsApp, or Signal.

Here's a breakdown of what that implies:

• No Internet Required (Ideally): SMS messages should be delivered as long as there is a cellular connection, even without an active data or Wi-Fi connection. However, this can depend on the carrier's implementation. Some carriers may rely on data for SMS delivery if certain conditions are met.
• Carrier Involvement: The message is routed through your mobile carrier's network.
• Basic Features: Text messages generally support only limited formatting options and a small character limit (typically 160 characters for SMS, though longer messages are usually split into multiple segments by the sending device/carrier and reassembled on the receiving end). MMS messages can accommodate richer content like images, audio, and video, but they still have size limits.
• Cross-Platform Compatibility: Because SMS is a universal standard, text messages can be sent to virtually any mobile phone number, regardless of the recipient's device type (Android, iPhone, etc.).
• Cost: Sending text messages may incur charges, depending on your mobile plan. Some plans include unlimited texting, while others charge per message. MMS messages are generally charged at a higher rate than SMS messages.
• Privacy and Security: SMS messages are not end-to-end encrypted, meaning your carrier and potentially other parties can access the content of your messages. They are considered less secure than internet-based messaging apps that offer end-to-end encryption.
• Fall Back Mechanism: In some cases, when sending to another user of the same internet based messaging service (like iMessage), if the internet connection is unstable or unavailable, the message may be sent as a standard text message as a backup.

In summary, "sent as a text message" indicates a lower-tech, but more universally compatible and (ideally) cellular network-dependent method of message delivery.