Differentiate between read-only and read-write transactions.

**Read-Only Transactions:**

1. **Purpose:** Only retrieve data without modifying it.

2. **Impact:** Do not affect the database state; no data is altered or written.

3. **Concurrency Control:** Typically have less stringent concurrency control requirements since they do not change data.

4. **Performance:** Often optimized for speed and efficiency, as they avoid the overhead of locking mechanisms and data modification.

5. **Examples:** Querying records, generating reports, or performing data analysis.

**Read-Write Transactions:**

1. **Purpose:** Retrieve and modify data, including inserting, updating, or deleting records.

2. **Impact:** Change the database state, affecting data consistency and integrity.

3. **Concurrency Control:** Requires robust concurrency control mechanisms to manage data consistency and handle conflicts during simultaneous access.

4. **Performance:** Can be more complex due to locking and transaction management to ensure data integrity and consistency.

5. **Examples:** Processing orders, updating user profiles, or making financial transactions.