This is not the definition of a monopoly.
What Apple (and Amazon) are being accused of is predatory pricing to root out competition. Monopolies are not bad because they raise prices. Over the long-run, the tend to do so, but raising prices itself is not "bad."
Monopolies are prosecuted when they use their position to discourage competition, which stifles innovation. That's what Apple is in trouble for, by lowering prices such that less-funded incumbents cannot enter the market. That's what $MSFT was in trouble for with IE. Yes, they gave away a browser for free, but in the process abused their power as distributor of Windows to corner another market. No company could reasonably compete with a pre-installed browser, meaning $MSFT would be discouraged from innovating.
In some instances, monopolies are a natural conclusion of free-market dynamics. Centralizing production into one entity maximizes possible economies of scale (ain't no scale like 100%!) Most government programs are based on this principle. The assumption is the NASA, bringing together the financial and technical capabilities of the entire United States, has the best opportunity to advance aeronautic engineering.
In other instances, monopolies use their position to prevent competition. These are the bad guys and gals. Think Standard Oil or the old AT&T. Sometimes, multiple independent companies will collude to form a cartel and abuse their collective market power. Airlines do this by raising ticket prices together, despite no external force (like higher taxes, union wages, or oil prices.)
NASA is a great example of a monopoly that does not abuse its position. It actively encourages competitors (e.g. SpaceX) by granting the contracts.
EDIT: Replaced incorrect usage of "market power" with "predatory pricing". Thank you @baddox and @chipotle_coyote for the corrections.