Is computer operating systems an example of pure competition near monopoly monopolistic competition oligopoly?

Computer operating systems primarily exhibit characteristics of an oligopoly. A few dominant firms, such as Microsoft and Apple, control a significant share of the market, leading to limited competition. While there are alternatives available, the high barriers to entry and the established brand loyalty make it difficult for new competitors to gain substantial market share. Thus, the operating system market is not purely competitive or monopolistically competitive, but rather an oligopolistic one.