Are there different TYPES of Corona Viruses – Anyone actually see someone with the symptoms?

Some groups may wonder if there is a Stronger or Weaker VERSION of the Corona Virus, or if there are just different variations that may be created as a result of the unknown source of instigation. Does that mean that the Virus can get stronger if it has the opportunity to merge with other Viruses, or that the Virus can gain intelligence by using its existing intelligence?