You can implement a condition by using either of the following ways:

     =>   By creating a rule condition - Specifies that you can implement conditions either directly in code or by using a tool, called the Rule Condition Editor. Rule conditions are stored in a separate Extensible Markup Language (XML) file. When a rule condition occurs in a workflow, the expression in a condition is evaluated and a Boolean value is returned.

     =>   By creating a code condition - Refers to defining a condition directly in code. A code condition can be created by writing a method in the code. The method contains code for the condition and returns a Boolean value.

Workflows serve the purpose of automating business processes. Now, since each type of business has a wide range of problems; therefore, a workflow platform needs to be extensible. WF provides you with a set of base activities, such as IfElse, Code, and Delay, to build a workflow. You can extend these activities or build new activities to meet your requirements. Besides activities, you can also extend services, such as tracking, management, and persistence, provided by the runtime engine.

In WF 4.0, the following two types of workflows are used:

 
     Flowchart workflows - Helps you to create workflows using the common flowchart elements. In WF, the Flowchart activity is generally used to implement a non-sequential workflow, and occasionally it implements sequential workflows in case the FlowDecision nodes are not used. The Flowchart activity contains a collection of flow nodes, which inherit from the FlowNode class. The following types of nodes or elements can be a part of a flowchart:
                 => FlowStep - Executes activities of a flowchart in a sequence.
                 => FlowDecision - Shows the execution on the basis of a Boolean condition.   It is similar to the If construct.
                 => FlowSwitch - Shows the execution on the basis of an exclusive switch. It is similar to the Switch construct.


      Procedural workflows - Helps you to create workflows using basic and sequential execution standards. In WF, procedural workflows use flow control constructs, such as While, Switch, ForEach, and If, to execute activities. These flow control constructs are similar to those found in procedural languages. Procedural workflows can also contain other flow control activities, such as Flowchart and Sequence.

Windows Workflow Foundation (WF) is a technology that was first introduced in .NET Framework 3.0. WF consists of a programming model, a workflow runtime engine, workflow designer, a rules engine, and tools to quickly build workflow-based applications on Windows. WF facilitates the separation between the business process code and the actual implementation code.