Acer is the genus, and is capitalized. Genus and species will be discussed more later. All names come from Latin or Greek roots, because those were the languages of educated people at Linnaeus' time. In the generally accepted system, there are 5 Kingdoms. The defining characteristic is that all organisms develop from an embryo with a blastula stage.
Animals also have senses and nervous systems, to aid in locamotion and searching for food.
The main characteristic is that plants develop from an embryo without a blastula stage and have cellulose in their cell walls. They are autrophs, organisms that can make their own food. Plants produce food through photosynthesis, and have chloroplasts for this purpose. Most are immobile. A few eat insects for extra nutrients, such as the venus fly trap.