Plants grow fastest when they get the proper amount of light, water and soil. How a plant thrives is dependent on the species, whether they are placed inside or outside.
When buying seeds or starter plants, the packaging provides information on how to care for the plant, including how much light the plant requires and how often it needs water. Some plants are bred to be grown indoors, and they will grow quickly inside. Indoor plants require potting soil, which has extra nutrients and drains faster than soil from the yard. Indoor plants also have to be watered, whereas plants outside may be able to live off the rain.