There are a few different symbols that you might see on your Android phone's call log. Here's what they mean:
Outgoing call: A green phone icon next to a call indicates an outgoing call.
Missed call: A red phone icon next to a call means that you missed the call.
Incoming call: A blue phone icon next to a call means that the call was incoming.
Answered call: A blue checkmark next to a call means that you answered the call.
Voicemail: A red circle with a slash through it next to a call means that the call went to voicemail.