Throughput refers to how many transactions a system can process over a period of time.
TPS stands for transactions per second and is the generally accepted measure of throughput.
If someone refers to Radix as being ”scalable,” they are referring to the fact that the Radix Public Network can grow larger and with more throughput without facing bottlenecks or degradation in performance.
Scalability is vital because as DeFi becomes more mainstream, the number of transactions will increase dramatically as a large number of new users flood the network and transact on it. If a network cannot handle these transactions, it cannot grow.
There are no fundamental theoretical limits to the total number of independent transactions Cerberus can process concurrently in distinct shards. This is what allows Cerberus to scale linearly with the number of nodes.