We are talking about the floating point number format and the behavior of computer programming languages. In “mathematics”, the meaning of the symbol ∞ depends

We are talking about the floating point number format and the behavior of computer programming languages. In “mathematics”, the meaning of the symbol ∞ depends on what number system we are talking about. In some contexts ∞ is not a “number”, but rather a shorthand for a statement about limits. In other contexts it is a number. If you want to learn about the “affinely extended real numbers”, which is what floating point numbers more or less approximate, you can read https://en.wikipedia.org/wiki/Extended_real_number_line https://en.wikipedia.org/wiki/Extended_real_number_line