Boolean algebra? That's not electronic, that's pure math and logic. It can just be and commonly is implemented with electronic circuits, but you can just as well make a logical AND gate with mechanical elements, whether they are cogwheels, or valves with flowing water or air pressure.
In Boolean algebra, there are variables that are either true or false. Statements can be constructed to be true or false, such as is it day or night, does it rain, or is it cloudy.
However, as you already might have seen, just like in electronics, there is always a gray area between day and night, where given a bunch of people they will not all agree on the exact moment when day turns into night or vice versa.
Which means, even electronic circuits are not strictly digital in as even digital logic is implemented by using analog components and circuits.