When does data insertion into a table take more time: with indexes created or without them?

Inserting data into a table takes more time if indexes are created on the table. This is because, when adding each new record, the DBMS must not only insert the data into the main table but also update all related indexes to keep them current. Without indexes, insertion is faster since there is no need to update additional structures. However, having indexes speeds up queries and searches, so their use is a trade-off between insertion speed and read efficiency.