Shebang (Unix)
Imagine you have a magic tool that can do anything you tell it to do. Let's call it "Bash". Now Bash doesn't know what to do on its own - you have to tell it what to do.
When you open a script in Linux (which is just a bunch of instructions for Bash), the first line of the script tells Bash which magic tool to use to turn your script into actions. So "shebang" (or "hashbang") is just the magical phrase that tells Bash which program to use for your script.
This is important because different scripts might need different magic tools. For example, if you're writing a script in Python, you want Bash to use Python as the magic tool to run your script. So you'd put something like this at the top of your script:
#!/usr/bin/python
This tells Bash to use the Python program (which lives in the /usr/bin directory) to run your script. And just like that, your Python script is ready to go!
When you open a script in Linux (which is just a bunch of instructions for Bash), the first line of the script tells Bash which magic tool to use to turn your script into actions. So "shebang" (or "hashbang") is just the magical phrase that tells Bash which program to use for your script.
This is important because different scripts might need different magic tools. For example, if you're writing a script in Python, you want Bash to use Python as the magic tool to run your script. So you'd put something like this at the top of your script:
#!/usr/bin/python
This tells Bash to use the Python program (which lives in the /usr/bin directory) to run your script. And just like that, your Python script is ready to go!