Partial Views and ViewComponents are both used to create reusable UI parts in ASP.NET Core MVC. Although they may look similar at first, they serve different purposes.

A Partial View is best suited for rendering a reusable piece of HTML with a model passed from the parent view. It should not contain database access or complex logic. Examples include post cards, simple form fragments or footer sections.

A ViewComponent is more powerful. It has its own class, can use dependency injection, access the database and prepare its own model before rendering. This makes it ideal for dynamic menus, dashboard widgets, latest posts or category lists.

The simple rule is this: use Partial Views for reusable markup and ViewComponents for reusable UI blocks that need their own data logic.