Explanation
Two kinds of queries that the methods in Salesforce B2B Commerce services perform by default are SOQL and schema-less queries. SOQL is the query language that is used to retrieve data from Salesforce objects and fields. Schema-less queries are queries that do not specify the object or field names explicitly, but use placeholders instead. For example, ccrz.ccServiceDao.getQuery('SELECT Id FROM Account WHERE Name
= :name') is a schema-less query that uses :name as a placeholder for the field name. The framework will transform this query to use the actual field name based on the query transformation rules. Salesforce References: B2B Commerce and D2C Commerce Developer Guide, Query Transformation

Explanation
The method that needs to be implemented when rendering a Salesforce B2B Commerce view in order to have it called after rendering has finished is postRender. This method is an optional hook that can be defined by the user to perform any actions or logic that depend on the view being rendered, such as initializing widgets, binding events, or updating the user interface. The method will be called by the render method of the CCRZ.View class, which is the base class for all views in the framework. Salesforce References: B2B Commerce and D2C Commerce Developer Guide, View Class

Explanation
n: The Commerce Product Data Import resource is the recommended tool for importing products for a B2B or B2C store using a .csv file. This resource supports importing data of related objects, such as ProductCatalog, ProductCategory, Product2, and ProductCategoryProduct, while preserving their relationships. It also does not require additional licenses or third-party tools. The other options are either not specific to Commerce products, or do not support importing data of related objects. References:
* Commerce Product Import Resource
* Import and Export Commerce Data
* B2B and D2C Commerce Data Model

Three advantages of using ccLog over the Salesforce standard System.debug class are:
There is no need to use string concatenation to easily tag log statements with a subject. ccLog allows passing a subject parameter to the log method, which will prepend the subject to the log message. For example, ccLog.log('This is a message', 'Subject') will log [Subject] This is a message.
There is no need to create a User Trace Flag. ccLog can be enabled by setting the value of CO.logToken to true in CCAdmin, which will activate logging for all users who access the storefront.
There is no need to manually set a cookie to debug with the Site Guest User. ccLog can be enabled for the Site Guest User by appending #ccLog=<Logging Token Name> to the end of the storefront URL in order to get logs in the inspector console. For example, https://my-storefront.com/#ccLog=debug will enable logging for the Site Guest User with the debug level. Salesforce Reference: B2B Commerce and D2C Commerce Developer Guide, Logging