The capital got moved to Berlin (the BRD had former had it's capital in Bonn, the DDR had it's in East-Berlin).

A new kind of tax was introduced, the "Solidaritätszuschlag" (solidarity tax).

The money was then used to get the standards equal. It's not perfect even today, but we're coming close.

Parts of the "NVA" (East-Germany's Army) were integrated into the "Bundeswehr".

That should be about it. If there's anything more precise you might want to know, then please ask me.