VoLTE, which stands for Voice over Long-Term Evolution, is a technology utilized by phones and carriers around the world to transmit our voice(s) during calls. It's supported by just about every modern smartphone out there, even those from a few years ago. Unless you have an extremely old device, you're probably already using VoLTE on a near-daily basis, even if you don't realize it.
As wireless carriers (both mainstream service providers and MVNOs) in the United States continue to expand upon and improve their 5G network infrastructure, LTE (which is often called 4G) has become the default fallback option where 5G doesn't have strong coverage yet. VoLTE, as its name suggests, is based on LTE and is available across the vast majority of the country. Even if you have a newer smartphone but you're not already using VoLTE, it's a good idea to switch over to it.
