Doubt on port in HFSJ

In HFSJ,onpage 21,page discusses about port.I had a question.They say port is 16 bit number that identifies software programme running on the server.For example port 80 identifies HTTP software that runs on server.They also gave "Using one server spp per port,a server can have up to 65536 different server apps running.although it is possible to run more than one app on the same port if the apps use different protocols)" Does this mean HTTP softare that is running on port 80 can be configured to accept different protocol?Can anybody please explain elaborately what does sentence in bold mean?

This may not be important exam point of view.But was just curious about understanding the port concept!

Thanks
Veena

ya i am also interested to know the above query >>..

regards

Although it is possible to run more than one app on the same port if the apps uses different protocols

Yes this is TRUE.

Consider ServletRequest and ServletResponse. Servlet spec has these interfaces keeping in mind that some one might develop application that doesn't uses HTTP Protocol.

So the application is developed using servlet technology thats running in port 80 but might use a different protocol.