JavaScript has a few built-in primitive types. One of them is a Boolean, which can have the literal values, true or false. Another primitive type is number which can hold any floating point 64 bit value. Then there is string, which can hold any number of characters, for example, the text world. In addition to these primitives, there are two special primitives for absence of teta undefined to indicate if a value is not yet defined and now, which is used

to indicate if a value is not present. Now, modern JAL script also introduces to additional primitive types, the symbol type to create globally unique identifiers and a big inch type to hold arbitrarily large whole numbers. TypeScript provides predefined lowercase type names for these JavaScript primitives. These names actually follow what these types are called within the JavaScript spec, so if we wanted, we could annotate a bullion as a variable of type bullion. The number as a variable of type number, the string

as a variable of type string, and four, undefined and null. There are predefined literal types, undefined and no, and for the symbol there is a predefined type symbol. And for biggins there is a predefined type bigint. Now, type names and TypeScript generally follow the Pascal case convention. The only type names that are lowercase per default are these types as these are known as primitive types in JavaScript and are fundamental to how JavaScript works.