Explanation
Use the terraform providers command to view the specified version constraints for all providers used in the current configuration.
https://www.terraform.io/docs/configuration/providers.html

Explanation
The Terraform language will automatically convert number and bool values to string values when needed, and vice-versa as long as the string contains a valid representation of a number or boolean value.
Example
* true converts to "true", and vice-versa
* false converts to "false", and vice-versa
* 15 converts to "15", and vice-versa
Where possible, Terraform automatically converts values from one type to another in order to produce the expected type. If this isn't possible, Terraform will produce a type mismatch error and you must update the configuration with a more suitable expression.
https://www.terraform.io/docs/configuration/expressions.html#type-conversion

Explanation
For production use, you should constrain the acceptable provider versions via configuration file to ensure that new versions with breaking changes will not be automatically installed by terraform init in the future.
Example
terraform {
required_providers {
aws = ">= 2.7.0"
}
}

Explanation
If you are new to infrastructure as code as a concept, it is the process of managing infrastructure in a file or files rather than manually configuring resources in a user interface.
A resource in this instance is any piece of infrastructure in a given environment, such as a virtual machine, security group, network interface, etc. At a high level, Terraform allows operators to use HCL to author files containing definitions of their desired resources on almost any provider (AWS, GCP, GitHub, Docker, etc) and automates the creation of those resources at the time of application.