[Question]: variables instead of locals

[Imany-apk]

Is it possible to use variables instead of locals?
Is locals usage just for clean code?

[Shayan-Ghani]

We typically use locals to collect data from different components and then strip them to something we wish to achieve. here are some examples using functions:

locals {
names = ["Alice", "Bob"]
greetings = ["Hello", "Hi"]

concatenated_list = concat(local.names, local.greetings)
concatenated_string = concat("Hello ", "World!")
}

locals {
words = ["Hello", "World", "Terraform"]

joined_string = join(", ", local.words)
}

locals {
numbers = [1, 2, 3, 4, 5]

doubled_numbers = map(local.numbers, multiply(2))
}

Also, this is what chatgpt says which is quite fine:
Variables are meant to define input values that can be passed to Terraform when executing a plan or apply operation. They allow for flexibility and customization by allowing users to provide different values for those variables based on the environment or specific requirements.

Locals, on the other hand, are used to define intermediate values within the Terraform configuration. They can be derived from variables, data sources, or other resources. Locals help improve the readability and maintainability of the code by providing a way to store and reuse values within the configuration.