As described earlier, the lwIP
sequential API provides a straightforward and easy-to-use method of
interfacing to the stack. Unlike the raw API, which requires event-driven
callbacks, an application can simply call the API functions as needed
to perform stack operations such as sending data, receiving data, or
manipulating packet buffers or connections. While the raw API may allow
for more efficient operation, the sequential API typically allows for
simpler application design.