**Explanation:**

An association is a connection or link between two or more things. In this context, the association refers to a connection established between common elements or characteristics.

**Relationship:**

The correct answer is option 'B' - Relationship.

A relationship is a type of association that exists between two or more entities or objects. It represents how these entities are connected or related to each other. In the context of databases, a relationship is established between tables based on common attributes or fields.

**Example:**

For example, let's consider a database for a school. We may have two tables - one for students and another for classes. The students' table may have fields like student ID, name, age, and class ID. The classes' table may have fields like class ID, class name, and teacher name.

To establish a relationship between these two tables, we can use the common field - class ID. By linking the class ID field in the students' table to the class ID field in the classes' table, we can associate each student with their respective class. This relationship allows us to retrieve information about a student's class or a class's students.

**Importance of Relationships in Databases:**

The establishment of relationships between tables is crucial in database design and management. It helps in organizing and structuring data efficiently, reducing data redundancy, and ensuring data integrity.

**Types of Relationships:**

There are different types of relationships that can be established between tables:

1. One-to-One (1:1) Relationship: This type of relationship occurs when one record in the first table is associated with only one record in the second table, and vice versa. For example, a person and their passport information.

2. One-to-Many (1:N) Relationship: This type of relationship occurs when one record in the first table is associated with multiple records in the second table, but each record in the second table is associated with only one record in the first table. For example, a customer and their orders.

3. Many-to-Many (N:N) Relationship: This type of relationship occurs when multiple records in the first table are associated with multiple records in the second table. This type of relationship requires the use of a junction table or intermediate table. For example, students and classes.

In conclusion, an association established between common elements or characteristics in a database is referred to as a relationship. This relationship helps in organizing and managing data effectively, ensuring data integrity, and enabling efficient retrieval of information.