What are two features of a DBMS that ensure transactions meet the ACID properties? List and shortly explain them code example

Example 1: acid properties

Atomicity 
Consistency
Isolation  
Durability

Example 2: acid properties in dbms

Atomicity
The entire transaction take place at once or doesn't happen at all.

Consistency
Database must be consistent before and after the transaction.

Isolation
Multiple transactions occur independently without interference.

Durability
The changes of the successful transaction occurs even if the system 
failure occur.