Both Apple Inc.'s AAPL, +2.55% iOS and Microsoft's Windows are expected to gain market share over the next few years, while Google Inc.'s GOOGL, +4.16% GOOG, +4.20% is expected to decline slightly, according to IDC.
What is the relationship between 'share' and 'Windows' in the context of the input sentence.
Options: stock exchange, headquarters location, platform, currency