Triton virtual machines (VMs) are hardware virtual machines (HVMs) wrapped in highly secure zones, supporting a variety of images including Linux, FreeBSD, Windows, and Docker Engine. They offer a solution for a wide variety of applications that have certain operating system dependencies or applications that can't be run in a containerized environment. Triton offers support for these applications via hardware virtualization but there are some differences between infrastructure containers and virtual machines to be aware of.
Infrastructure containers run on top of a bare metal hypervisor. They do not run a separate guest OS, resulting in better performance, scalability, and stability than a hosted hypervisor. All VMs get the same high performance networking stack, regardless of the instance type or size.
Live resizing of HVM instances is not supported. Infrastructure containers can be resized to add memory, CPU, and disk space without rebooting, but the nature of hardware virtualization does not allow that convenience.