It is customary to actually ask a question in this space.
Judging from your heading, though, you want to know the difference between a CR2032 and a CR2025 battery.
The only thing you can count on at all is size: the CR2025 will be 2.5mm thick, instead of 3.2mm thick.
There's more room inside the bigger battery, so the CR2032 will _probably_ have more capacity and slightly higher current capability, but the battery manufacturer is free to put whatever they want inside the case: they could even use the CR2025 innards in a CR2032 shell, to save production costs.
If you need to know how a battery is going to perform in a specific application, your best bet is to look at data sheets from specific manufacturers (the good ones do publish these; some even publish accurate ones). Use the data sheet to verify that the battery will or won't do what you need.
There's probably more advantage to be had by buying a really good name brand CR2025 over a cheap no-name one than there is to be had by going from a no-name CR2025 to a no-name CR2032.