Zera means seed, offspring, descendants, or posterity. It appears about 230 times. The 'seed' promises are among Scripture's most important theological threads, running from Genesis 3:15 to Christ.
The 'seed' promise runs from Genesis 3:15 (the seed of the woman crushing the serpent) through Abraham's seed (Genesis 22:18), David's seed, to Christ — the ultimate Seed (Galatians 3:16). This single word creates a redemptive thread binding the entire Bible together.