robots are automated scripts that crawl, search, or perform requests for information.
Ben Werdmüller runs a bot that responds to requests for information on his own site:
Active or Passive
One interesting distinction between bots are ones that are active where you have to ask it a specific question. Such bots are: Ben Werdmüller's bot, Siri, Alexa, Google Home, etc. A passive bot is more like Slack bots that might be prompted by certain text that happens. Also Loqi would be considered a passive both with some active options. Much of what Loqi does is watching natural conversation on IRC and replying to it. Although, specific questions around What is... or Who is or When is... could be considered active.