Hello Abhishek
In the past, before the advent of the switchport voice vlan command you would have to configure a port as a trunk port that included both the voice and data VLANs. It was around 10 years ago when I was first learning about Cisco IP telephony where we would use such a configuration. Back then, connections to IP phones were literally trunks.
Today however, we use ports configured with voice VLANs. Such a port will have both the switchport mode access command as well as the switchport voice vlan command. So is this an access port or a trunk?
They are often referred to as “a special type of 802.1q trunk”. This makes sense since 802.1q tagging is included in the frames that are in the voice VLAN. However, Cisco has (more correctly in my opinion) referred to such a port as a @multi-VLAN access port."
Really, you can take your pick of what to call it, just realise that 802.1q tagging takes place on the voice frames and does not on the data frames.
I hope this has been helpful!
Laz