Help MySQL find rows faster without scanning an entire table for every query.
Indexes are data structures that help MySQL locate rows more efficiently. Without an appropriate index, the database may need to examine a large part of a table before finding the records that match a query.
Indexes can make reads much faster, but they also consume storage and add work when rows are inserted or updated. Good indexing means creating indexes around the queries your application actually runs rather than indexing every column.
What you'll walk away knowing