Analog is the opposite of digital. Any technology, such as vinyl records or clocks with hands and faces, that doesn't break everything down into binary code to work is analog. Analog, you might say, is strictly old school.
The original definition of analog is something that is similar to something else; the two are said to be analogous. In technological terms, it means something that has an output that's proportional or similar to its input — usually a voltage. Anything digital is the exact opposite: whatever comes out the other end bears no relationship to the soup of binary code that goes in. The word can also be spelled analogue.