https://m.academy/articles/magento-2-request-response-lifecycle/

https://tiagosampaio.com/2023/06/19/front-controller-the-guy-who-handles-the-request-in-magento-2/

Types of Controller Response in Magento 2 

There are five Controller Response Types in Magento

•  Page
• JSON 
• ROW 
• Redirect 
• Forward

(01) Page: This returns HTML loaded from a layout handle.

(02) JSON: this returns a response in JSON format. It can be used in API or AJAX requests.

Magento\Framework\Controller\Result\JsonFactory;

$result = $this->jsonFactory->create();

$data = ['success' => true, 'message' => 'Data fetched successfully']; return $result->setData($data);

(03) Raw: this returns whatever you want to be returned.

Magento\Framework\Controller\Result\RawFactory;

 $result = $this->rawFactory->create();

$result->setHeader('Content-Type', 'text/plain');

$result->setContents('This is a plain text output'); return $result;

(04) Forward: this internally forwards to another

Create a file at  etc/adminhtml/system.xml for that specific module.

In the system.xml file, it is possible to define four different types of entities those are below

Create a tab:

<?xml version="1.0" ?>
<config xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="urn:magento:module:Magento_Config:etc/system_file.xsd">
    <system>
        <tab id="A_UNIQUE_ID" translate="label" class="a-custom-css-class-to-style-this-tab" sortOrder="10">
            <label>A meaningful label</label>
        </tab>
    </system>
</config>

Only id is required

Create a Section:

<?xml version="1.0" ?>
<config xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="urn:magento:module:Magento_Config:etc/system_file.xsd">
    <system>
        <tab id="A_UNIQUE_ID" translate="label" class="a-custom-css-class-to-style-this-tab" sortOrder="10">
            <label>A meaningful label</label>
        </tab>

        <section id="A_UNIQUE_SECTION_ID"

Certification journey for Adobe Commerce Developer Professional

Roadmap and complete guide if you want to be a certified developer for Magento 2

Following are website link which helps you to prepare for exam.

https://www.study4exam.com/magento/free-magento-2-certified-associate-developer-questions

Some useful website links

https://devdocs.magento.com/guides/v2.4/extension-dev-guide

https://github.com/magento-notes/magento2-exam-notes/

https://github.com/pykettk/magento2-developer-exam-notes

https://belvg.com/tutorial/magento-2-certified-professional-developer-guide-section-2

AD0-E702

https://spark.adobe.com/page/ClHLYMaUjTUfa/

https://www.certmetrics.com/adobe/candidate/exam_scheduling.aspx?%20redir=yes

Below is exam for AD0-E711 Adobe Commerce Developer Professional

https://express.adobe.com/page/saM506xrYKi0p/

All exam list