C++11 is the modern C++ standard published in 2011. This brought many major extensions and improvements to the existing language. It was approved by International Organization for Standardization (ISO) on 12 August 2011 and replaced C++03.
C++11 was also known as C++0x. This is because, For the next revision, it was supposed that the next Standard after would be done by 2008, but since it was uncertain, it was named C++0x, where the x stood for either 8 or 9. Though planning shifted and it is now called C++11. So, C++0x was the name for the standard before it was published. Once it was finalized in 2011 it was named C++11.
Following are the major changes/additions of C++11 −
And many more. You can get the complete list with examples at https://en.wikipedia.org/wiki/C%2B%2B11.