A very common use-case in Lightning Web Component is iterating a list over an array in HTML file using for:each or iterator directive. Many times as a developer, we have to do something on the items based on user interaction. You would definitely require to get selected record id from custom iteration.
Salesforce introduce Launch Pad standard Lightning Component you can add to any Lightning page. They create a shortcut to important places for your users. You can add any items that have tabs associated with them—standard and custom objects, Lightning web components, Lightning pages, Visualforce pages, and external websites.
Lightning Web Component is the new way of building Lightning Components in Salesforce. There are high chances that you may end up with some common error.
UNDERSTAND GETTER IN LIGHTNING WEB COMPONENT
OPEN LIGHTNING COMPONENT FROM URL BUTTON IN LIGHTNING
When name attribute is defined in slot element, it is known as named slots where as slot without a name attribute is called unnamed slots.