This is explained in the tutorial available on this link.
<span style="color: rgb(0, 0, 0); font-family: Roboto, sans-serif, Arial, Verdana, Tahoma; font-size: 16px; background-color: rgb(255, 255, 255);">Exceptions allow a method to react to exceptional circumstances and errors (like runtime errors) within programs by transferring control to special functions called handlers. For catching exceptions, a portion of code is placed under exception inspection. Exception handling was not a part of the original C++. It is a new feature that ANSI C++ included in it. Now almost all C++ compilers support this feature. Exception handling technology offers a securely integrated approach to avoid the unusual predictable problems that arise while executing a program.</span>