What is true about hotspots and bottlenecks in HPC application debugging?
1) Hotspots and bottlenecks are the same thing in HPC application debugging
2) Hotspots and bottlenecks are different concepts in HPC application debugging
3) Hotspots refer to areas of code that consume a significant amount of execution time
4) Bottlenecks refer to areas of code that limit the overall performance of the application