A second interview may probably be with other people if the first interview was with somebody from the HR department who was doing the first screening. Present at the second interview will probably be your future departmental boss, and possibly somebody from another department such as IT if the job is of a technical or computer-based role for example, or somebody who is familiar with the work.
I suspect they will be wanting to test your ability to perform the role according to the job description (presume you asked for one and were given a copy), and background on your previous job, the tasks you performed and how you solved any difficult problems which came your way. They may also want to test your interpersonal skills and see how you would fit it with the rest of the team, and how promotable you are in the longer term., and whether you bring any new skills which are not possessed by other members of the team. You may be asked some of the same questions again, but possibly from a different angle. This will also be your opportunity to ask more detailed questions about the job, what the skills are in the rest of the team and how you might fit in, plus how the company would help you develop and enhance your own skills within the department by providing extra training, exposure to new learning situations, etc.