What is shipping_price in Shipping plugins

Array
(
    [5] => stdClass Object
        (
            [shipping_id] => 5
            [shipping_type] => custom_manual
            [shipping_zone_namekey] => 
            [shipping_tax_id] => 0
            [shipping_price] => 6.15
            [shipping_currency_id] => 5
            [shipping_name] => Custom Plugin
            [shipping_description] => Test
            [shipping_published] => 1
            [shipping_ordering] => 1
            [shipping_params] => stdClass Object
                (
                    [shipping_percentage] => 0
                    [shipping_per_product] => 1
                    [shipping_price_per_product] => 1
                    [shipping_override_address] => 0
                    [shipping_override_address_text] => 
                    [shiptoschool] => 1
                    [other_name] => Other
                    [other_price] => 20
                    [shipping_warehouse_filter] => 
                    [shipping_min_price] => 0
                    [shipping_max_price] => 0
                    [shipping_virtual_included] => 1
                    [shipping_price_use_tax] => 1
                    [shipping_min_quantity] => 
                    [shipping_max_quantity] => 
                    [shipping_min_weight] => 
                    [shipping_weight_unit] => kg
                    [shipping_max_weight] => 
                    [shipping_min_volume] => 
                    [shipping_size_unit] => m
                    [shipping_max_volume] => 
                    [shipping_zip_prefix] => 
                    [shipping_min_zip] => 
                    [shipping_max_zip] => 
                    [shipping_zip_suffix] =>                   
                    [shipping_min_price_orig] => 
                    [shipping_max_price_orig] => 
                )

            [shipping_images] => 
            [shipping_access] => all
            [shipping_price_orig] => 5.00000
            [shipping_currency_id_orig] => 2
            [shippingkey] => 0
            [shipping_price_base] => 5.1539484398998
        )

)