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In this video, we are going to learn a step function core concepts which are the state machine states

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task space, weight, choice, parallel, succeed and fail.

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So let me start with the state mission.

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You can see the all caucus state in this list.

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I'm going to start explaining state mission in computer science.

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A state mission is defined as a type of computational device that is able to store various status values

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and update them based on the inputs.

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So it's a function which with this concept and use the state machine to refer to an application workflow.

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Developers can build a state machine in state functions with JSON files by using the Amazon State language.

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We can choose a standard workflow for processing that are long running tasks and also include the required

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human intervention.

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And also we can choose express workflows or suite for short running and high volume processes.

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So let me continue with the state.

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What is the state, state or element in our state machines?

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A state is referred by its name, which can be anything but which must be unique within the scope of

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the entire state machine.

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So individual states can make these decisions based on their input, perform actions and test output

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to other states.

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In step functions, we define our workflows.

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In the Amazon State language, the state functions console provide a graphical representation of that

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state machine to help visualize our application logic.

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So a state represent a step in our workflow so states can perform a variety of functions.

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You can think that all below items are state and these are the state options.

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For example, the state perform work in the state machine, which we call the task state and or we can

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chose between different parts in a workflow.

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This is the choice state or it is a stop the workflow.

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With the failure or success, we can give an example of fail or success state or this will be passed

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output or some fixed data to another state.

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It is a test state or it is a path to workflow for a specific amount of time.

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This is the way it state or we can begin parallel branches of execution.

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This is the parallel state or it can repeat execution for each item in the input.

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This is the map state.

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So the state that we decide to include in our state machine and the relation between our states form

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the core of our step function workflows.

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So now let me elaborate the task state tasks.

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State can be divided by two, which will be the activity task and the service task.

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It may explain the task state.

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A task state within your state machine is used to complete a single into a work task can be used to

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call the API actions of over the 200 Amazon services.

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Or we can perform another task which perform the complete operations.

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So there are two types of task can be included in our workflows.

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One is the activity task, the another is the service tasks.

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Let me explain activity tasks.

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Activity tasks basically connect a step in our workflow to batch code that is running elsewhere.

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This external batch of code called an activity worker post the step function for work and asynchronous

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to complete the work using our code and return the result.

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This is the Activity Task and activity task are common with the asynchronous workflow in which some

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human intervention is required.

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So these are the activity tasks that we can perform in the task state.

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And another task in the task state is service task.

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A service task let you connect steps in our workflow to specific services, set functions, send requests

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to other services, wait for the task to complete and then continues to next step in the workload.

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They can be used easily for automated steps, for example, executing lambda function.

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These are the service tasks.

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So basically within our console we are able to visualize and validate our set mission with using the

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step functions.

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So step functions provide the visualize and create our workflows very efficiently and very easily.

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So you can see this slide in the image here.

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You can see the for example, state name is a work delegate that performs a natively lambda function.

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You can see an example state in here.

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The name of the state is Helloworld and this is basically perform the helloworld lambda function.

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You can see the type as a task.

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The source is a lambda function.

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So this is the service task and you can see the next state and the command of this state.

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So basically state shares many common features.

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Each state must have a type field indicating what type of the state is.

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And also each state can have an optional command field that basically understand from the humans.

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And also each state requires a next field if it is not a succeed or failed state.

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That should be a next step.

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And alternatively, we can become a terminal state or by specifying the unfilled.