Is tenant in common the same is co-owner?

No, a tenant in common is not necessarily the same as a co-owner. While both terms refer to individuals who hold an ownership interest in a property, "tenant in common" specifically describes a legal arrangement where each owner has a distinct share of the property that can be sold or transferred independently. Co-ownership can encompass various forms, including joint tenancy and tenancy by the entirety, each with different rights and implications.