Association:
An association describes a group of links with common structure and common semantics.

Example:
A person works for a company. It is often APPEAR verb in the problem statement. It is implemented as a pointer or reference to an object

Aggregation:
An aggregation is the "a part of" relationship in which objects represents the components in same assembly. Aggregation may be the special FORM of Association.

Example :
A PARAGRAPH consists of many sentences. Here Paragraph contains sentences.

Inheritance:
Inheritance is a relationship between a class and one or more redefined version of it. It is sometimes CALLED "is a relationship.

Association:
An association describes a group of links with common structure and common semantics.

Example:
A person works for a company. It is often appear verb in the problem statement. It is implemented as a pointer or reference to an object

Aggregation:
An aggregation is the "a part of" relationship in which objects represents the components in same assembly. Aggregation may be the special form of Association.

Example :
A Paragraph consists of many sentences. Here Paragraph contains sentences.

Inheritance:
Inheritance is a relationship between a class and one or more redefined version of it. It is sometimes called "is a relationship.