In general, ground cover refers to any ornamental plant that requires little attention and can be used provide a compact, low growing, carpet between other plants or used to soften landscaped areas.
Not only will ground cover suppress weeds, it can provide very a attractive backdrop to other planting schemes.
Ground cover can be used to provide an alternative soft ground surface instead of a lawn or a paved area, especially in a small garden where a lawn is not so practical. In many situations ground cover plants can be a very useful alternative to grass, for example, in deep shade under trees or on large banked areas where a lawn can be difficult to maintain. Although not as robust as grass, certain low gowning plants can actually be walked-on but they will not usually stand up to regular foot traffic.
Ground cover is also useful in beds and borders, as in-fill between larger spot plants. It can also be used to create a bold area of planting, especially in problem areas such as deep shade where little else will grow. Ground cover is also a useful infill between paving to prevent the encroachment of weeds.