Composer is a cross-platform dependency manager for PHP libraries.

In this guide, I am installing Composer on my macOS Big Sur.

First navigate to the user directory, i.e cd/User/

Run the command shown below to download composer to the navigated directory:                 

sudo curl -sS https://getcomposer.org/installer | php

We need to create a directory, so run the following command to create a directory:

sudo mkdir -p /usr/local/bin

Now, we need to move composer.phar to the created directory Run the command:

sudo mv composer.phar /usr/local/bin/composer

Now, we need to let Bash know the path to the Composer, so run the command

nano ~/.bash_profile

Add the below code to the bash_profile and save 

alias composer="/usr/local/bin/composer.phar"

Now, run the following command to specify the source for bash_profile

source ~/.bash_profile

Finally, run the following command to check whether the installation was successful

composer