A terrace is an external, raised, open, flat area in either a landscape near a building, or as a roof terrace on a flat roof.
A terrace
A terrace of the Joenniemi Manor in Mänttä-Vilppula, Finland
A terrace at the shores of Lake Purgatsi in Anija Parish, Estonia
Franciscan friars look at the sea and city landscape from a terrace in Rio de Janeiro, Brazil, c. 1816
A patio is an outdoor space generally used for dining or recreation that adjoins a structure and is typically paved. In Australia, the term is expanded to include roofed structures such as a veranda,
A patio outside of a home in the Netherlands
An outdoor seating area at a restaurant in State College, Pennsylvania