The Events module in Node.js extends the 'EventEmitter' class to allow the creation of event emitter instances. This class provides the functionality for registering event listeners and emitting events.

A JavaScript file that uses the export keyword is considered a "module." Modules are used to encapsulate and export functionality that can be used in other parts of the code.

The primary purpose of the NPM (Node Package Manager) registry in Node.js development is to host and distribute Node.js packages and modules. It serves as a centralized repository for sharing and discovering reusable code, making it a crucial component of the Node.js ecosystem. Option 1 is incorrect because NPM is not used to install Node.js itself; you would use a Node.js installer for that. Option 2 is incorrect because NPM primarily manages packages on a project-specific level, not globally. Option 4 is incorrect because the NPM registry is not used to execute JavaScript code directly.

The Time-To-Live (TTL) value in caching determines how long the data should remain in the cache before being expired. When data expires, it is removed from the cache and, if needed, can be fetched again from the source.

When evolving schemas in distributed databases, it's important to apply changes sequentially with backward compatibility. This means making changes in a way that allows both old and new versions of the schema to coexist temporarily, ensuring data consistency during the transition. Applying changes simultaneously or only to a single node can lead to data inconsistencies.

To ensure maximum security and flexibility in a RESTful API, you should use JWT for authentication, as it allows for stateless authentication and can be used across different client types. Fine-grained middleware can be used for authorization, controlling access to specific endpoints. The other options are insecure or impractical approaches.

Closures help implement Creational design patterns in JavaScript. These patterns deal with object creation mechanisms, and closures enable the preservation of state within functions, aiding in pattern implementation.

In EJS (Embedded JavaScript), you use <%= %> to output data to the template and <% %> to execute JavaScript code within the template. The other options are not valid EJS syntax.

Defining relationships in a database schema is crucial for improving data integrity and consistency. Relationships help maintain referential integrity, ensuring that data remains accurate and reliable when related records are updated or deleted. While relationships can impact query complexity and storage, their primary purpose is to maintain data quality.

Closures can be used to create private variables in JavaScript by declaring variables inside a function. These variables are not accessible from outside the function, effectively creating encapsulation and data hiding.