The format of the find command is: If you do not specify a path, find starts in the current working directory and looks through all subdirectories for the specified pattern.
The find command has many options that you can review by entering man find at a shell prompt. The most common option is -name, which tells find to search for all files and directories with a certain string of letters in their name.

find . -name foo
 

The above command searches through the current working directory for all files with "foo" in their name.