When you type the ping command, your asking the system to send a packet of data, and then wait for a reply.(an echo).
The output you see is the size of the ICMP packet sent to the host you specified(google.com or the IP address google resolved to. ) in this case 64 bytes. The ICMP_seq is just a runnning count of the number of packets sent to the host.
ttl (Time To Live). This means if the echo ( reply from host) is not received within the time period, the packet is lost and the therefore did not reply.
time is the “round trip time” ie the amount of time it took for your linux system to send the icmp packet and get the response back from the host ( google.com )
Hope this helps.