A backtrace is a summary of how a program got to a certain point. It’s often used in debugging to figure out what sequence of function calls and events led to a particular error or crash. The backtrace provides a list of function calls that are currently active in a thread.

Here’s a simplified example:

1. main() (the starting point of the program)
2. functionA() called by main
3. functionB() called by functionA
4. functionC() called by functionB

If functionC() causes an error, the backtrace would look something like this:

1. functionC()
2. functionB()
3. functionA()
4. main()

This backtrace tells you that functionC() was called by functionB(), which was called by functionA(), which was originally called by main(). This can be useful to understand the “path” taken through the program to arrive at the error.

In real-life situations, backtraces can be significantly more complex due to things like recursion, multiple threads, or complicated control flows. But the principle remains the same: it’s a way to trace the path of execution that led to a specific point in the code.