Solved: How to download a complete S3 bucket or a S3 folder?

If you ever want to download an entire S3 folder you can do it with CLI.
You can download the AWS CLI from this page. AWS CLI Download
Download the AWS CLI as per your system Window, Linux or Mac.
In our case we use Windows 64 bit. Once you donwload the .exe simply double click on it to install the AWS CLI.
Once the AWS CLI is installed go to windows command prompt(CMD) and enter command

aws configure

It will ask for the AWS user details with which you want to login and region name. Check this post to know How to create an IAM user.
You can get the AWS IAM user access details from IAM console .
Get Region name here .
Fill in the user details as below:

AWS Access Key ID: <Key ID of the user>

AWS Secret Access Key: <Secret key of the user>D

region Name : <us-east-1> 

Default output format: None

Once you have downloaded and configured AWS CLI on your machine you have to exceute “sync” command as shown below.

aws s3 sync s3://mybucket/dir  /local/folder

You can also do the same with “cp” command. It will need –recursive option to recursively copy the contents of subdirectories also.

aws s3 cp s3://myBucket/dir /local/folder --recursive

Refer to this S3 cheat sheet to learn more tricks.