(US here.) As a person who used to hire employees, yes, I conducted reference checks. It was required by the company. My process was to review applications and resumes, conduct a telephone interview, and then bring in the final candidates for a personal interview.
Once the list of candidates was down to one to three, reference checks would be conducted. The same list of questions were used for each candidate and within the law. The minimum was three.
I never called anyone listed as a personal reference; only those that were listed as previous employers. Despite the US laws, it’s amazing what information a former supervisor will share, and as @syz points out, what they convey by tone of voice.
The company I worked for didn’t allow us to be a reference for employees. There was an 800 number we were to give out that directed the inquirer to an HR record-keeping hotline. However, if it was an internal candidate, there was a little more leeway.
As for questions asked, they included the standard “Can you confirm dates of employment?”, “Would you rehire this person?”, etc. Most were based upon work performance. What any objective information a hiring manager expects to get from a personal reference is beyond me.