What is the meaning of platform?

noun

• A raised horizontal surface.
  • usage: "the speaker mounted the platform"
• A document stating the aims and principles of a political party.
  • usage: "their candidate simply ignored the party platform"; "they won the election even though they offered no positive program"
  • synonyms: political platform, political program, program
• The combination of a particular computer and a particular operating system.
• Any military structure or vehicle bearing weapons.
  • synonyms: weapons platform
• A woman's shoe with a very high thick sole.
  • synonyms: chopine