If you can imagine a spectrum of research paradigms, interpretivism would sit more or less on the opposite side of the spectrum from positivism.
Essentially, interpretivism takes the position that reality is socially constructed. In other words, that reality is subjective, and is constructed by the observer through their experience of it, rather than being independent of the observer.
The interpretivist paradigm typically underlies studies where the research aims involve attempting to understand the meanings and interpretations that people assign to their experiences. An interpretivistic philosophy also typically manifests in the adoption of a qualitative methodology, relying on data collection methods such as interviews, observations, and textual analysis. These types of studies commonly explore complex social phenomena and individual perspectives, which are naturally more subjective and nuanced.