Ir's a Dieffenbachia, the common name is 'dumb cane' due to its poisoning effect on the throat due to raphides. Does not need to be pruned at all, water from the bottom and keep the soil moist.

yep, wash hands after handling & it should come with a warning label especially where children are concerned. If the sap gets on your tongue it swells up preventing you from speaking hence it's common name.

Actually, it's an Aglaonema brevispathum, close kin to Chinese evergreen (A. modestum). It is also related to Dumb Cane, and isn't good for eating, but usually isn't a medical emergency. This one looks like it could use some more indirect light, and maybe a bit of plant food.