const objSealed = { value: 11 }
const objFreezed = { value: 11 }

Object.seal(objSealed)
Object.freeze(objFreezed)

objSealed.value = 22
objFreezed.value = 22

objSealed.foo = "bar"
objFreezed.foo = "bar"

delete objSealed.value
delete objFreezed.value

console.log(objSealed) // { value: 22 }
console.log(objFreezed) // { value: 11 }