I'm trying to follow the SMS read tutorial and don't understand the following line:

// Read message bytes and print them

What is c exactly? Is it each character from the message being printed individually or all of them in a character array? How could I combine all the characters into a character sequence. Any explanation would be appreciated.

c is a char that is read from circular buffer of the library. c is each character.

When you receive a SMS message, it content is saved in a circular buffer to be read by sketch.