magento2 – What is load method in magento 2 model how it’s works with magento 2 model


i have doubt in

Magento 2 Model

when i use this in some places not getting brand value (Graphql Resolver) like cart details

  $product=$value('model');


  $brand=$product->getAttributeText(self::BRAND_ATTRIBUTE_CODE);

but

when i use like this

if($brand===false){
            $product->load($product->getId());
            $brand=$product->getAttributeText(self::BRAND_ATTRIBUTE_CODE);
        }

i am getting expected value

what happening behind the load () in model

and how it’s works ?

(Is there any disadvantages there)

Thanks in advance