Magento

TermDescriptionReferences
Magento Open Source or MagentoThe Magento Open Source project! Magento Open Source software delivers basic eCommerce capabilities to build a unique online store from the ground up.https://github.com/magento/magento2https://business.adobe.com/products/magento/open-source.html
Magento APIThis is an acronym to talk about Admin Rest API or Graph QL Admin API. For HexaSync and documents related to using HexaSync to connect Magento to other applications, we often abbreviate to “Magento API ” instead of Magento Admin API.https://developer.adobe.com/commerce/webapi/rest/https://developer.adobe.com/commerce/webapi/graphql/ 
Magento API ResourceHowever, we can understand it as some kind of merchant data provided through a Magento API Endpoint.https://developer.adobe.com/commerce/webapi/ 
Configurable ProductYour products are the goods, digital downloads, services, and gift cards that you sell. You add a product to Magento by entering product details and uploading product images. If your product has options, like size or color, then you can add a variant for each combination of options.https://experienceleague.adobe.com/en/docs/commerce-admin/catalog/products/types/product-create-configurable 
Simple ProductYou add variants to a product that comes in more than one option, such as size or color. Each combination of option values for a product can be a variant for that product. It is called Simple Product.
For example, suppose that you sell T-shirts with two options: size and color. The size option has three values: small, medium, and large. The color option has two values: blue and green. One specific variant from these options is a small, blue T-shirt.
https://experienceleague.adobe.com/en/docs/commerce-admin/catalog/products/types/product-create-simple 
Entity-Attribute-Value (EAV) and extension attributesAttributes help you to customize the functionality and appearance of your Magento store by letting you save specialized information that isn’t usually captured in the Magento admin. You can use attributes for internal tracking, or to display specialized information on your online store in a variety of ways.https://developer.adobe.com/commerce/php/development/components/attributes/