This specific update introduced several quality-of-life improvements and bug fixes:
This is a compression format; you will need software like WinRAR or 7-Zip to extract the actual NSP files inside. Key Features of Update 1.2.0 Pokemon Viola (NSP)(Aggiornamento 1.2.0).rar
This is a digital file format used for Nintendo Switch software, typically representing games or updates downloaded from the eShop. Pokemon Viola (NSP)(Aggiornamento 1.2.0).rar