Are these lenses AF 50mm f/1.8D and AF-S 50mm f/1.4G FX and low light shooting?

Hello,
I have the following lenses AF 50mm f/1.8D and AF-S 50mm f/1.4G.

Are they FX or DX ?

Are they good for low light shooting ?

Thanks for your help,

both are for either FX or DX... and both can do low light but the 1.4G will be slightly better for lower light shooting.

Thanks a lot skene.