When working with TypeScript, you often need to describe the shape of data that consists of multiple properties grouped together. This is where object type annotations come in. Object types let you specify exactly what properties an object should have and what types those properties must be. This concept is sometimes called the type shape of an object. By defining a type shape, you give TypeScript the information it needs to catch errors when objects do not match the expected structure.

In object types, you can control which properties are required and which are optional. By default, every property you declare in an object type is required—the object must have that property, and it must match the specified type. If you want to allow a property to be omitted, you can mark it as optional by adding a question mark (?) after the property name. This flexibility lets you model objects that may or may not include certain data.