The iPhone 5c was created, because people wanted iPhone's in different colors. They also created a gold iPhone. This is consumer sovereignty. They wanted colorful iPhone's so apple produced them.
Apple and Android are constantly in competition. One of their main competitors are the iPhone and Android Phones. This is an example of competition.
Walmart is an example of a market. There are many goods and services provided here. Prices are provided and goods are sold. People have economic freedom to buy what they want in Walmart.
This is another example of competition within companies. Converse and Vans are two famous shoe companies. They are constantly battling with each other to have more people buy their shoe. Therefore prices aren't ridiculously high, and consumers can enjoy affordable shoes.