What does it mean to say that something is "true"?

People are at the human/opinion level and, to some extent, use logic truth and/or reality truth.

Many people have difficulty distinguishing between opinion based in reality and/or logic and opinion not based on reality and/or logic.

Logic tends not to work with people who do not think logically. These areas can overlap but the distinction is, nonetheless, useful. All humans work at the level of opinion, but more or less connect that opinion with reality truth and/or logical truth.

Logical truth: symbol manipulation involving integer values, which is exact but may involve paradoxes. This includes coded information, programming languages, digital computers, etc.

Mathematics is concerned with logical without any connection to reality. (Mathematicians such as Hilbert made this decision in the early 1900's).

In the 1920's, Hilbert (1928) proposed finding a consistent mathematical system that will allow all possible truths
to be decided. This would allow the automatic, or mechanical, proving of all possible truths.

Hilbert invented/discovered the Hilbert curve, a monster curve that was not fully understood until the introduction of fractals a half-century later. Logical truth involves mathematical and computer/information logic using two discrete logic values (e.g., true and false, 1 and 0) and symbol manipulation using rules to determine which claims are "true" or "false".

Computer logic and programming involves logical truth.

Hilbert and his problems and the separation of math with reality and philosophy.

Note that generalizations of logical truth can involve paradoxes, incompleteness, undecidability, etc.

Reality truth: approximations using all math values, probability and statistics, etc., which may use logical truth. Traditional science involves reality truth.

Reality truth involves what exactly is real, or reality. Reality truth involves probability, statistics, approximations, unknowns, etc. The traditional scientific method involves reality truth. So does, to some extent, the traditional legal process.

Opinion truth: all other types of truth, which may or may not use logical and reality truth, but need not do so.

Human truth can be whatever one or more humans decide it is. Thus, there are no precise rules for defining human truth other than it is not necessarily logical truth or statistical truth.

In a programming languages course, one is primarily concerned with logical truth. There may or may not be any connection of logical truth with reality truth and/or human truth.

Thus, a Boolean condition that is either true or false may or may have no connection to "reality".