The major difference between these two strategies has to do with the attitudes that they hold towards trade.
An outward oriented growth strategy is one that sees trade as the way for a country to develop. A country relying on such a strategy wants to have free trade (at least for its exports). It wants to allow goods and services to flow freely around the world. By contrast, an inward oriented growth strategy is one that would prefer autarky. Such a strategy will seek to restrict trade so that it can create its own, relatively self-sufficient domestic economy.
In reality, most countries use a combination of these two, trying to push free trade in areas where they export but to restrict it in ways that can protect domestic industries.