Logical OR vs Logical Addition
The + operator has different meaning depending on the operands (1 and 1 in your case), e.g.:

Decimal numbers: 1 + 1 = 2 (decimal), where + means decimal addition
Binary numbers: 1 + 1 = 10 (1 is carried over for 1 bit), where + means binary addition
Logical / Boolean: 1 + 1 = 1, where + means logical OR
Text: &quot;abc&quot; + &quot;def&quot;, where + means text concatenation
Array/Lists: [1, 2] + [3, 4] = [1, 2, 3, 4], where + means list concatenation

Actually, + can be defined depending on the context, where the first three examples are assumed trivial, and the last two can be used in some programming languages, all using the same '+' sign/operator to denote different functions/meanings.