We can allow 2 concurrent incoming callers at one time. Any additional calls after that will be sent directly to voicemail if voicemail is enabled on the account. If voicemail is not enabled, callers will hear a busy signal, and the calls will show up with zero minutes in the call log.
Some other companies might refer to these as "lines" or "call paths." Regardless, they all refer to the same thing. If you require more concurrent calls than this, please contact customer support so we can determine if we can support your specific use case.