Yes, it's all correct.
Your first visa (spousal visa) was a Limited Leave to Enter visa, which is only granted outside the UK and is an initial visa allowing you to enter the UK to live.
Your second visa is FLR(M) = Further Leave to Remain (Marriage). This is an extension visa only granted inside the UK, allowing to you remain in the UK once you are already living here.
Your third visa will be ILR = Indefinite Leave to Remain. This is also an extension visa only granted inside the UK, allowing you to remain in the UK permanently.