This is when the objects are deformed or stick together. Momentum is still conserved in these situations, but this time the objects do not escape the collision unharmed. And unlike elastic collisions, inelastic collisions do give off quite a bit of heat when the two objects come together.
From Wikipedia: Curtana, also Cortana or Courtain, is a latinized form of the Anglo-French curtein, from Latin curtus, 'shortened', used for a ceremonial type of sword. [...] Curtana was also, according to legend, the sword of Ogier the Dane; it bore the inscription My name is Cortana, of the same steel and temper as Joyeuse and Durendal..
Cortana is the name for the intelligent personal assistant and knowledge navigator for Windows Phone 8.1 and Windows 10. Cortana builds off Microsoft's previous voice technology called TellMe, purchased by Microsoft in 2009. Cortana competes against Apple's Siri and Android's Google Now voice assistants. The name 'Cortana' comes from the fictional, artificially intelligent (AI) character in the Halo video game series. The first evidence of Cortana's existence was found in June 2013 in the Windows Phone Central forums, appearing as 'zCortana' from a developer device that was accidentally sold to a non-Microsoft employee.