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Now when working with union types like this and this can be cumbersome to always repeat the union type

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you might want to create a new type which he store is this union type and you can do that with a number

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of cool types would feature the feature of type aliases you create such alias typically before you use

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it.

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So here at the top of the file in this case here with the type keyword now to type keyword is not built

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into javascript.

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It's supported in typescript though and after type you add the name of your custom type or of your type

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alias I should say for example combined label but the name is really up to you.

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You can invent any name here which is not built into JavaScript or typescript as a key name something

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like date would not be allowed because that's built into javascript but combined ABL is not built into

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javascript not built into typescript so we can use it.

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And now with an equal sign you assign the type you want to encode in your alias.

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So to say so we could store a number here and now whenever we want to make sure that something should

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be a number we could use combined ABL instead.

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Now that doesn't make too much sense.

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It arguably would even make our code harder to read.

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If I use combined a down there for example this would work technically but if we just glance over our

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code it's not obvious that here we want a number or a string.

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Well typically therefore you use that in conjunction with union types so we can store a union type in

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our custom type so to say in our type alias.

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And now just refer to combine them all down there instead of our union type.

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So we have exactly the same setup I asked before.

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We just have our reusable type alias here which we can use instead and that allows us to save some extra

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code and make sure we always refer to the same types or the same type setup when we use combined all.

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And of course we can not just use that for number and string.

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We can use that for any type setup we might want to stored in an alias including these two literal types

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for example.

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So for these two types here for this union type we could also create a type alias conversion descriptor

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or however you want to name it and store exactly this type in this type alias.

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And now we can use this type alias down there.

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So type aliases are really really useful.

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You can encode more complex type definitions into your own types into your own type names.

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So to say and reuse that everywhere in your code where you need exactly this type setup.

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So did you have wide typos down there and you can simply save code write code quicker and also be clearer

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about your intentions for example by choosing descriptive type alias names up there.