The expression 10 / 0 evaluates to Infinity in JavaScript. Unlike some programming languages that throw an error for division by zero, JavaScript has special numeric values to represent the result of such operations. Dividing a positive number by zero results in Infinity, dividing a negative number by zero results in -Infinity, and 0 / 0 results in NaN. These are all valid values in JavaScript's number type, and operations can continue after producing them, though they may lead to unexpected results.