a use case diagram is a graphic depiction of the interactions among the elements of a system

Purpose: Describes a set of actions (use case) that some system or systems (subject) should or can perform in collaboration with one or more external users of the system (actors) to provide some observable and valuable results to the actors or other stakeholders of the system

use case allow to capture requirement of systems under design or consideration, describe functionality provided by those systems, and determine the requirement the system pose on their environment

an actor is behaviored classifier which specifies a role played by an external entity that interacts with the subject (e.g., by exchanging signals and data), a human user of the designed system, some other system or hardware using services of the subject

a subject of a use case defines and represents boundaries of a business, software system, physical system or device, subsystem, component or even signal class in relation to the requirements gathering and analysis

extend is a directed relationship that specifies how and when the behavior defined in usually supplementary (optional) extending use case can be inserted into the behavior defined in the extended use case

use case include is a directed relationship between 2 use cases which is used to show that behavior of the included use case (the addition) is inserted into the behavior of the including ( the base ) use case

purose:Shows structure of the designed system, subsystem or component as related classes and interfaces, with their features, constraints and relationships - associations, generalizations, dependencies,

Purpose:Instance level class diagram which shows instance specifications of classes and interfaces (objects), slots with value specifications, and links (instances of association).

Purpose:
Shows packages and relationships between the packages.

Class diagram show a collection of classes , interface ,acciations,collaborations, and contrains

An Object diagram show relatiton between the
instantiated classes and the defined class
and the relation between these object in the system

Every object is actually symbolized like
a rectangle that a offer the name from object and it class underlined as well as divided with a colon

Linked tend to be instances
assiociated with associations.You can draw a link while using the lines utilzed in class diagram

Similar to classes you are able to list object attributes inside a separate compartment.However, unlike classes,Object atrributtes should have values assigned for them

Package diagramga kind of structural diagram,show the arrangement and organization of model elements in middle to large scale project.Package diagram can show both structure and dependencies between sub-system or modules showing different views of a system

A composite structrute diagram is a UML structural diagram that contrains classes,interfaces ,package and their relationships that provides a logical view of all or part of a software system.It show the internal structrue of a strutured classifer or collaboration