Take one minute of video. Look at the file size. Now how many of these 1 minute files can you fit onto an 8GB card in your particular format and camera/device.
SMS stands for Short Message Service, which is the formal name for text messaging. It's a way to send short, text-only messages from one phone to another. These messages are usually sent over a cellular data network. That's not always true, though, as in the case of iMessage below.
SMS Messaging and MMS Differences. There are several differences in SMS and MMS messaging. Bulk SMS messages are sent via cellular networks and are started by the message transferring to something call a short message service center or SMSC for short. The SMSC then attempts to send the messages to the recipients.