Why is wear leveling important for EEPROM/Flash and how is it implemented?

EEPROM and Flash have limited write/erase cycles (10K-100K typically), requiring wear leveling to extend lifetime by distributing writes evenly across memory. Techniques: Circular buffer: Append new data to next location, wrap around; simple for log-like data. Swap areas: Alternate between multiple areas for frequently updated data. Sector remapping: Abstract logical to physical sector mapping; rotate physical sectors. Write counter tracking: Monitor sector write counts, avoid high-count sectors. Implementation considerations: Store metadata about current write position. Use valid/invalid markers to find latest data. Handle power-loss during write (journaling). Reserve spare sectors for bad block replacement. Calculate expected lifetime: (total writes per sector x number of sectors) / writes per day. File systems like littlefs and SPIFFS include wear leveling for Flash storage in embedded systems.