Emacs has several different major modes for Lisp and Scheme. They are the same in terms of editing commands, but differ in the commands for executing Lisp expressions. Each mode has its own purpose.
The mode for editing source files of programs to run in Emacs Lisp. This mode defines C-M-x to evaluate the current defun. Section 25.7.
The mode for an interactive session with Emacs Lisp. It defines C-j to evaluate the sexp before point and insert its value in the buffer. Section 25.9.
The mode for editing source files of programs that run in Lisps other than Emacs Lisp. This mode defines C-M-x to send the current defun to an inferior Lisp process. Section 25.10.
The mode for an interactive session with an inferior Lisp process. This mode combines the special features of Lisp mode and Shell mode (Section 31.15.3).
Like Lisp mode but for Scheme programs.
The mode for an interactive session with an inferior Scheme process.
Most editing commands for working with Lisp programs are in fact available globally. Chapter 24.