^ Caret symbol is used to escape special characters in string of ms dos commands. For example > is used to write output to the file but > has to print with the echo command. But it is not escape by echo command because > is used to write echo  output to the file.

 echo welcome > filename.txt
It writes welcome to the file.

 echo a > b means a is big > filename.txt
It write only a to the file. because > has different meaning in the command line. so > has to escape with ^ caret symbol like below.

Valid statement with caret escape character symbol.
 echo a ^> b means a is big > filename.txt

also escape < less than symbol also with ^ caret symbol
echo ^<script^> > hello.html

To escape % symbol in batch file is %%. %% percentage is equals to single %.