[javascript] about ‘prototype’

When searching for method about Object or Array in mdn, there express some ‘prototype’. like Object.prototype.valueOf() or Array.prototype.filter().

I don’t know what is that meaning about prototype. is that meaning something doesn’t finished or complete?

and the answer is prototype is literally prototype properties of Object.

for example, trying below code in console.

const obj = {};

after execute that code, it’s appear about some object include method like valueOf!

but when trying to print just ‘obj’ is print empty object.
but, it’s has prototype!

so, it’s make sense using the word ‘prototype’!

it’s inspired and references by Just Javascript ([Just JavaScript] 09. Prototypes) from Dan Abramov