Psychology focuses on the study of an individual’s mental health and attitudes. Think of a therapist who helps a patient through depression or extreme anxiety or a phobia of something.
Sociology focuses on the study of a community’s culture and attitudes. Think of political campaign managers who have to understand the population to help connect the politician with the voters. Or a marketing team who has to advertise a product – they have to know who the target audience of the product is, and then understand how to best present that product to that audience to make it as attractive as possible. There are more aspects to it, of course, but those are a couple easy examples of how it can be used.
Cultural anthropology is also a study of a community’s culture, but it is specifically to document that culture and understand how it relates to other aspects of that community’s life (their biological features, their environment, etc.). It can be the study of historical cultures or present day cultures or both.
Sociology focuses on groups/ multiple people as the unit of analysis, while psychology focuses on the individual. There is overlap because each field recognizes that the individual is never “just” an individual but always influenced by others (and even takes the perspective of others in its own minds).
Sociology is broader than cultural anthropology, and comes from a different academic disciplinary history, but includes the same topics: the meanings, practices, and artifacts of a particular culture, and how they work. Sociology also includes lots of topics besides “cultural meaning” itself, and many levels of analysis, from social psychology to economic behavior, to history of politics, etc.
Source: PhD/ B.S. in sociology from two top tier American universities