Case Sensitivity while declaring a database object in Oracle

Database objects are case-sensitive & will be treated as though they are typed in upper case.
This is generally true - but there is exception and its depends on whether you use double quotes " or not.

• If a name is not enclosed in a double quotes, then it will be treated as uppercase regardless of how is created or referenced.
• If a name is enclosed in a double quotes, then it is case sensitive and must always will be referenced with case sensitivity and double quotes

CREATE TABLE latte(Name Varchar2(20));

The database will automatically convert latte into LATTE.So you can reference table as 

Select * from latte;

            OR

Select * from LATTE;

CREATE TABLE "latte" (Age NUMBER);

Then every future reference will require double quotes and case sensitive reference to this.

Select * from "latte"; will work.

But

Select * from LATTE; not work. 

Not either this one

Select * from latte.

There is more !!! By using double quotes, you can also include special character that are otherwise not allowed -- space.

This will work

CREATE TABLE "java latte"(name varchar2(20));