In sql, the case expression 1) is a conditional expression that is the equivalent to the more general switch expression (same function, just another word).
As for a switch statement, there is also two ways to write a case statement:
CASE Promotions."Promo Subcategory"
WHEN 'TV commercial' then 'Commercial'
WHEN 'TV program sponsorship' then 'Sponsor'
ELSE 'Default'
END
CASE WHEN "Sales Facts"."Amount Sold" > 600000 THEN 'Big'
WHEN "Sales Facts"."Amount Sold" > 300000 THEN 'Middle'
ELSE 'Small' END