Composition and inheritance are both mechanisms for reusing code in OOP, but they differ in their approach. Composition involves creating complex objects by combining simpler ones, whereas inheritance involves creating a new class based on an existing class, inheriting its properties and behavior.

The command used to stage files for committing in Git is git add. This command adds changes to the staging area, preparing them for the next commit. It allows for selective committing of changes.

SDLC stands for Software Development Life Cycle. It is a systematic process for planning, creating, testing, deploying, and maintaining information systems.

AWS Lambda is the AWS service used for serverless computing. It allows developers to run code without provisioning or managing servers. It's a cost-effective way to build applications that respond to events and scale automatically.

In a banking application, ensuring data consistency during concurrent transactions is critical. Using database transactions provides a reliable method to maintain atomicity, consistency, isolation, and durability (ACID properties). This approach helps prevent issues such as lost updates or inconsistent states.

Text logs are typically human-readable and provide information about system events and errors. They are easy to interpret and analyze, making them widely used in logging for their simplicity and accessibility.

Caching in web development refers to storing frequently used data temporarily. It helps improve performance by reducing the need to fetch the same data repeatedly from the server.

Test-Driven Development (TDD) promotes writing tests that fail before writing new code to pass them. This iterative approach ensures that each new piece of code is validated against predefined test cases, contributing to a more robust and reliable codebase.

In online banking transactions, the use of ACID properties (Atomicity, Consistency, Isolation, Durability) is critical to ensure the integrity of financial data. A failed transaction could lead to inconsistencies in the user's account balance, emphasizing the need for transactional reliability.

The indexOf() method returns the position of the first occurrence of a specified character within a string. It helps in finding the index of a particular character or substring.