Differences between sequence diagrams and collaboration diagrams

The main differences between sequence and collaboration diagrams: sequence diagrams show time-based object interaction while collaboration diagrams show how objects associate with each other.

When you work in either a collaboration or sequence diagram, it is possible to view the corresponding diagram by pressing the F5 key. For example, if you are working on a sequence diagram, when you press F5, Rose will automatically create a collaboration diagram with the same diagram name and model elements. If you make a change to one diagram and then press F5, the change will appear on the corresponding diagram as well.

Note: When toggling from a sequence diagram to a collaboration diagram, you
might need to rearrange the collaboration diagram model elements.

====== COLLABORATION DIAGRAM:

Collaboration diagrams and sequence diagrams are alternate representations of an interaction. A collaboration diagram is an interaction diagram that shows the sequence of messages that implement an operation or a transaction.

Collaboration diagrams show objects, their links, and their messages. They can also contain simple class instances and class utility instances. Each collaboration diagram provides a view of the interactions or structural relationships that occur between objects and object-like entities in the current model.

The Create Collaboration Diagram Command creates a collaboration diagram
from information contained in the sequence diagram. The Create Sequence
Diagram Command creates a sequence diagram from information contained in the
interaction's collaboration diagram. The Goto Sequence Diagram and Goto
Collaboration Diagram commands traverse between an interaction's two
representations.

Collaboration diagrams contain icons representing objects. You can create
one or more collaboration diagrams to depict interactions for each logical
package in your model. Such collaboration diagrams are themselves contained
by the logical package enclosing the objects they depict.

======= SEQUENCE DIAGRAM

A sequence diagram is a graphical view of a scenario that shows object interaction in a time-based sequence of what happens first, what happens next. Sequence diagrams establish the roles of objects and help provide essential information to determine class responsibilities and interfaces. This type of diagram is best used during early analysis phases in design because they are simple and easy to comprehend. Sequence diagrams are normally associated with use cases.

Sequence diagrams are closely related to collaboration diagrams and both are alternate representations of an interaction. There are two main differences between sequence and collaboration diagrams: sequence diagrams show time-based object interaction while collaboration diagrams show how objects associate with each other.