This is a very brief summary:
Freshwater usually uses either t-8, t-5 or led
lights for plants. How "high" a tank is considered light depends on lighting, gallons of water and the depth of the tank. This factors in because it matters how much water light goes through. It becomes less effective as it goes down. A low light tank for a 10 gallon fresh would be like a single t-8 bulb. Medium like dual t-5 and high triple t-5 or higher. Once you start getting that high though you need co2
to help prevent algae. Again I am not an expert but this is some knowledge I believe to be correct.