Latency, Throughput and performance

The time that is required to pass the first byte to destination is called "Latency". Throughput is describes how many bytes of data are sent across network within certain time say one sec.
In the internet era, latency place more importance than throughput. say 5 secs are required to send data of 100 bytes and 300 bytes where as latency is different for these two activities. Fast or speed networks are difficult to reduce latency but they will increase throughput. Based on these two factors, designer has to look at the performance of the application while defining the architecture.