kali linux

Why when I type ping www.google.com the error unknown host. And when I type ping 8.8.8.8, the error appears network is unreachable. And when I type ping 0.0.0.0, it works ?? What is the difference between them and what do I do to work ??

Fri 20:08 root@kali: File Edit View Search Terminal Help root@kali:-#ping www.google.com ping: unknown host www.google.com root@kali:-# ping 8.8.8.8 connect: Network is unreachable root@kali:-# ping www.this website_does not exist.com ping: unknown host www.this website_does not exist.com root@kali: # ping 0.0.0.0 PING 0.0.0.0 (127.0.0.1) 56(84) bytes of data. 64 bytes from 127.0.0.1: icmp_seq=1 ttl=64 time=0.113 ms 64 bytes from 127.0.0.1: icmp_seq=2 ttl=64 time=0.027 ms 64 bytes from 127.0.0.1: icmp_seq=3 ttl=64 time=0.020 ms 64 bytes from 127.0.0.1: icmp_seqm4 ttl=64 time=0.023 ms 64 bytes from 127.0.0.1: icmp_seq=5 ttl=64 time0.023 ms 64 bytes from 127.0.0.1: icmp_seq=5 ttl=64 time=0.029 ms 64 bytes from 127.0.0.1: icmp_seq=7 ttl=64 time=0.032 ms 64 bytes from 127.0.0.1: icmp_seq=8 ttl=64 time=0.023 ms 64 bytes from 127.0.0.1: icmp_seq=9 ttl=64 time=0.023 ms 64 bytes from 127.0.0.1: icmp_seq=1 ttl=64 time=0.025 ms 64 bytes from 127.0.0.1: icmp_seq=11 ttl=64 time=0.025 ms 64 bytes from 127.0.0.1: icmp_seq=12 ttl=64 time=0.029 ms 64 bytes from 127.0.0.1: icmp_seq=13 ttl=64 time=0.029 ms 64 bytes from 127.0.0.1: icmp_seq=14 ttl=64 time=0.023 ms 64 bytes from 127.0.0.1: icmp_seq=15 ttl=64 time=0.021 ms C