Logstash-forwarder documentaion

At this time i am going with logstash-forwarder and will move to filefeat later. I have few queries can you help?

  1. If I am right logstash-forwarder will push the log to the ELK hosted server. What would be the path in ELK server where the logs will be pushed from logstash-forwarder. As I understand that we need to configure the log path with grok filter in logstash.conf

  2. What is the difference and relation among Filebeat, Libbeat, Packetbeat and Topbeat?