When preparing for an interview, do you use the job description or person specification?

[MaddenA]

I have an interview tomorrow. I'm currently prepping. Do employers tend to use the job description, or person specification when interviewing? Usually I mainly focus on the person spec but weirdly this job doesn't include much at all about the actual job in the person spec for desirable or essential. Equally. There are a few things on the job description that I have no experience with but assume this is fine as they're not in the person spec.

Any advice? My brain is starting to malfunction!

I evidence my skills and experience against the person spec, I assume they’ve figured out what they need in the staff member to do the job. I use the job description to identify areas of work I have experience in and to identify examples of my work I can use in interview to evidence the person spec, if that makes sense?

Both. Identifying how you fulfill the person spec should be how your application is scored, leading to you getting the interview. At the interview the questions may include some that are both broader & v specific to incorporate the JD & the PS. Think about what experience you have in relation to both, but just as important how you can address any gaps in your experience.