Columns explanation for Call reports

Twilio provider

Calls - all calls from customer which agents picked-up
Missed calls - count of calls which were not picked up in the time limit. 
The call is ringing to an agent for 30 seconds. If the agent doesn't pick it up within the 30 seconds, the call is rerouted to another agent and the first agent gets "missed call". If the second agent doesn't pick it up, he too receives a "missed call" and the call is rerouted again and so on until some agent picks up the call or the customer hangs up. If the same agent doesn't pick up again, he can receive more "missed calls" for the same call. Therefore this number can be larger than the number of incoming calls.
Incoming calls - all calls from customers. Contains calls picked-up by agents, but also calls when customer hang-up before the agent was connected.
Outgoing calls - agents calls from LiveAgent to customers
Call minutes - sum of call duration from all calls