After reading some articles, most people will say that sliceHeader is the essence of slice, so what is slice in slice.go?

so ?

“essence” is something abstract and metaphoric. What do you mean by it, are you interested on how slice objects look like at runtime ?

Yes, it’s not clear what sliceHeader does
my english is not very good, I used google translation

Have you read: Go Slices: usage and internals - (here’s a link translated into Chinese with Google translate).

There is no mention of sliceHeader related content here.

The “Slice internals” (Chinese) section describes how slices work. In the example, there are 3 fields: ptr, len, and cap. Those fields correspond to the slice struct’s array, len, and cap fields, respectively.