Go Arrays vs Slices Explained: Key Differences Beginners Need to Know

A tutorial published on DEV Community breaks down one of the most commonly misunderstood concepts for Go beginners: the difference between arrays and slices. Arrays in Go have a fixed size that is determined at creation, and that size is actually part of the data type itself, meaning [5]string and [6]string are entirely different types. Slices, by contrast, act as a dynamic view into an underlying array rather than independent data structures, which explains why modifying a slice can sometimes alter the original array. The article uses a bookshelf-and-picture-frame analogy to illustrate how slices reference existing data without copying it. Understanding this relationship helps clarify Go behaviors such as why append() can act unexpectedly and why slices are preferred over arrays in most real-world Go code.