Which of the following tools is considered the most portable?

The oscillating saw is considered the most portable tool among the options provided. This is primarily due to its lightweight and compact design, which allows for easy transport and maneuverability. Unlike larger tools such as the miter saw, table saw, and vertical band saw, which often require dedicated workspace and may not be easily moved without effort or assistance, the oscillating saw can be easily carried from one location to another.

Additionally, the oscillating saw is designed for versatility and can perform a variety of cuts, making it practical for various tasks on the go. Its power source can be either corded or cordless, further enhancing its portability. This combination of light weight, compactness, and ease of use in diverse settings makes the oscillating saw the most portable option among the listed tools.