An electronic device which emits a single shot/ pulse when triggered is considered monostable. However an electronic latch which oscillates between the two stable states commonly called a clock in a switch, this would be considered a free-running or astable. A latch is device which has two stable states and must be triggered to jump between the two stable modes, this is commonly called a flip flop and is used as temporary memory. Logic devices interpret the input voltages as either High or Low. Encoders and Decoders are used to translate from decimal to binary or vice versa. These are available in IC form.