Performance is characterized by the amount of useful work accomplished by a computer system compared to the time and resources used (Wikipedia).
This tag is intended to be used for performance related questions/problems, including:
- suddenly sluggish apps/system response (see e.g. My device is getting slow, apps start misbehaving/crashing. What can I do?)
- impact of certain things on performance (as in Does moving apps to the SD card negatively affect performance? or How do I speed up media scanning? -- but also Is the class rating of my MicroSD card relevant?)
- tracking down ressource issues having bad impacts on performance (as e.g. in How do I identify apps or settings that cause performance problems?)
- technical questions concerning performance tuning (as e.g. What is the effect of changing the maximum application VM heap size?)
For a closer explanation on the term, please see (Wikipedia).