Simple Definition:
SOS is a distress signal used to call for help in emergency situations. It is a universal code of three dots, three dashes, and three dots in Morse code (· · · – – – · · ·). [Morse Code is used on ship radio communication for instance, to transmit messages between ships]
For example: If a person is stranded on a deserted island and needs assistance, they could use SOS by lighting a fire or creating a sign using rocks or sticks.
Very Simple Definition:
SOS is a signal for help. It means “Please help me, I am in trouble!”
For example: If a person is lost in the forest and needs help, they can shout “SOS!” to attract attention from others.