Simplify the following text for a Grade 10 native English-speaking person.
Original: A digital signal is a physical signal that is a representation of a sequence of discrete values ( a quantified discrete-time signal ) , for example of arbitrary bit stream , or of a digitized ( sampled and analog-to-digital converted ) analog signal . The term digital signal can refer to
Simplified: In short , a digital signal is a quantized discrete-time signal ; a discrete-time signal is a sampled analog signal .