In this scenario, a Many-to-Many relationship is appropriate. This allows each employee to work on multiple projects, and each project to have multiple employees associated with it. It involves a junction table to manage the relationship.

In an ERD, a composite key is a key that consists of more than one attribute. It is used to uniquely identify an entity when a single attribute is not sufficient. Composite keys are common in situations where a combination of attributes is needed for uniqueness.

Aggregation in data modeling involves summarizing and combining data at a higher level. It is used to provide insights into the overall trends and patterns within a dataset, often involving the use of aggregation functions like SUM, AVG, COUNT, etc., to analyze and present data in a more meaningful way.

In a Star Schema, the central table is the Fact Table. This table contains the core data of the schema and is usually surrounded by Dimension Tables that provide context and additional details for the data in the Fact Table. The Fact Table typically contains numerical measures or facts that business users want to analyze.

Indexing improves query performance by creating a quick access path to the data. It reduces the number of records that need to be scanned, making data retrieval faster for specific queries.

In normalization, a transitive dependency occurs when a non-prime attribute determines another non-prime attribute. It violates the principles of normalization, and resolving such dependencies is crucial for achieving higher normal forms.

NoSQL databases often rely on eventual consistency in distributed systems compared to traditional relational databases. Unlike traditional databases that emphasize strong consistency through distributed transactions and ACID properties, NoSQL databases prioritize low-latency operations and high availability, accepting temporary inconsistencies that will eventually be resolved.

In denormalization, the creation of Aggregate tables is a technique to store precomputed results. These tables contain summarized data, reducing the need for complex calculations during query execution and improving overall performance.

Slowly Changing Dimensions (SCD) in data modeling are used to capture changes to dimension data over time. They allow for the tracking of historical data and help maintain a history of changes to dimensional attributes, which is crucial for analysis and reporting purposes.

In database design, "Forward Engineering" involves generating a database schema from a higher-level model, such as a conceptual data model. This process moves from an abstract representation to a concrete implementation, helping in the actual creation of the database structure.