Introduction:
Database transactions are a fundamental concept in database management systems (DBMS) that ensure the integrity and consistency of data. The ACID properties are the key characteristics of a transaction that guarantee its reliability and correctness. ACID stands for Atomicity, Consistency, Isolation, and Durability. This response will explain why "Integrity" is not an acid property of database transactions.

Explanation:
1. Atomicity:
Atomicity refers to the concept that a transaction is indivisible and either fully completes or is fully rolled back. It ensures that all the changes made within a transaction are committed as a single unit of work, or none of them are. This property prevents partial updates or inconsistencies in the database.

2. Consistency:
Consistency ensures that a transaction brings the database from one valid state to another. It enforces the integrity constraints and rules defined on the database, ensuring that the data remains valid and consistent throughout the transaction. If a transaction violates any constraints, it is rolled back, and the database remains unchanged.

3. Isolation:
Isolation refers to the concept that each transaction should be executed in isolation from other transactions. It ensures that concurrent transactions do not interfere with each other, maintaining data integrity. Isolation levels (e.g., Read Uncommitted, Read Committed, Repeatable Read, Serializable) define the degree of isolation and determine how the transactions interact with each other.

4. Durability:
Durability guarantees that once a transaction is committed and the changes are written to disk, they are permanent and will survive any subsequent failures. This property ensures that the changes made by a committed transaction are durable and can be recovered in the event of a system crash or power failure.

5. Integrity:
Integrity is not an ACID property of database transactions. Instead, integrity refers to the correctness, accuracy, and consistency of the data stored in the database. Integrity constraints, such as primary keys, foreign keys, unique constraints, and check constraints, are used to enforce data integrity by preventing invalid or inconsistent data from being stored in the database. While integrity is crucial for maintaining data quality, it is not specifically related to the properties of a transaction.

Conclusion:
In summary, the ACID properties of database transactions are Atomicity, Consistency, Isolation, and Durability. Integrity, although essential for data quality, is not one of the ACID properties. The ACID properties collectively provide a robust framework for ensuring the reliability, correctness, and durability of database transactions.