Freeze in Object:

Freeze method will lock’s the Object by which we cannot add new property and modify existing property value.

const obj = {
name: "angularfeed",
version: 2
}
Object.freeze(obj);// trying to modify the existing property value
obj.version = 3; // will throw error
// trying to add new property
obj.type = "academy"; // will throw error
delete obj.name; // throws error

Seal in Object:

Seal method will lock the Object but it’s property value can be change or modify but can’t add or delete new property to it.

const obj = {
name: "angularfeed",
version: 2
}
Object.seal(obj);// trying to modify the existing property value
obj.version = 3; // No Error
// trying to add new property
obj.type = "academy"; // will throw error
// trying to delete property
delete obj.version; // will throw error
Object.isFrozen(obj); // true for first Object
Object.isSealed(obj); // true for second Object