Question : What is the use of Node Manager in WebLogic

What is the use of Node manager

I can start the servers without using node manager. What is the necessity of Node Manager here?.
Also, Can I start all the managed servers at once using Node Manager through console or using WLST.

Thanks,
Nikhil

Answer : What is the use of Node Manager in WebLogic

http://edocs.bea.com/wls/docs103/nodemgr/overview.html

Nodemanager is for managing admin servers and nodes of your weblogic instances. You can start all managed servers through node manager. But based on the deployment and machines, it will takes its own time to startup.