Landscape architecture is the profession that practices the art of arranging or modifying the features of a landscape, an urban area, etc., for aesthetic and/or practical purposes.
This field must be distinguished from landscape design. The American Society of Landscape Architects asserts that someone who makes a career of "landscape architecture," properly speaking, possesses a higher level of skill, usually reinforced by a degree, than is possessed by a "landscape designer." Degrees and professional status notwithstanding, it is still accurate to say that members of the landscape architecture profession do practice landscape design.
In short, more training goes into entering the landscape architecture field than the landscape design field. Landscape architecture calls for a broader skill base and sometimes carries greater responsibility. For instance, a city or town may ask a landscape architect to design a park. A landscape designer, by contrast, is more likely to work on residential landscaping than on landscaping for a park.
Speaking of parks, Frederick Law Olmsted is recognized as the driving force behind the development of the landscape architecture field in the U.S. Olmsted masterminded Central Park in New York.
Do you need professional help for your residential landscaping? Many of my tips on how to find a landscape architect will come in handy, whether you end up hiring an actual landscape architect or a landscape designer.
Or perhaps you have a career interest in this area (in the wider sense)? You may wish to begin researching your interest by learning how to become a landscape designer.