What is the meaning of upgrade?

noun

• An upward slope or grade (as in a road. )
  • usage: "the car couldn't make it up the rise"
  • synonyms: ascent, acclivity, rise, raise, climb
• Software that provides better performance than an earlier version did.
• A reservation that is improved.
  • usage: "I got an upgrade to first class when coach class was full"
• The property possessed by a slope or surface that rises.
  • synonyms: rise, rising slope
• Hardware that provides better performance than an earlier version did.
• The act of improving something (especially machinery) by raising it to a higher grade (as by adding or replacing components. )
  • usage: "the power plant received a new upgrade"

verb

• Rate higher; raise in value or esteem.
• To improve what was old or outdated.
  • usage: "I've upgraded my computer so I can run better software"; "The company upgraded their personnel"
• Give a promotion to or assign to a higher position.
  • usage: "John was kicked upstairs when a replacement was hired"; "Women tend not to advance in the major law firms"; "I got promoted after many years of hard work"
  • synonyms: promote, advance, kick upstairs, raise, elevate
• Get better travel conditions.
  • usage: "I upgraded to First Class when Coach Class was overbooked"
• Give better travel conditions to.
  • usage: "The airline upgraded me when I arrived late and Coach Class was full"