Sorry & Apology.

Being a foreign user of english, I am not familiar with the usage of few words.

If the purpose of using 'Sorry' and 'Apology' be the same, then what is the difference. In my search to find the answer, I found that 'Apologize' is more formal whereas "I'm sorry" is more heartfelt and also express pity or sympathy.

There are places where you can only use 'Sorry'. (ie) Only 'Sorry' can be used to mean "to feel concerned about something". For Example : "I'm sorry that you lost your job"