Based on your description, it seems you're referring to the structure of the Roman Republic. Here's a breakdown:
- The Senate was appointed by the consuls or the Roman people (in some contexts, by censors) for life.
- Consuls were elected by the Centuriate Assembly or the Comitia Centuriata for one year.
- Assemblies were elected by the Roman citizens for one year.
In terms of which group could approve or veto laws, the Senate had significant power over legislation, as they could advise and influence decisions and had the ability to veto certain actions. However, the assemblies, specifically the Popular Assemblies, had the power to approve or reject laws. Therefore, the Senate could prevent or influence laws, while the assemblies were the ones that would formally vote on and approve them.