What is Vim recording and how can it be disabled?

You start recording by q and you can end it by typing q again.

Recording is a really useful feature of Vim.

It records everything you type. You can then replay it simply by typing @. Record search, movement, replacement...

One of the best feature of Vim IMHO.

Type :h recording to learn more.

*q* *recording*
q{0-9a-zA-Z"}           Record typed characters into register {0-9a-zA-Z"}
                        (uppercase to append).  The 'q' command is disabled
                        while executing a register, and it doesn't work inside
                        a mapping.  {Vi: no recording}

q                       Stops recording.  (Implementation note: The 'q' that
                        stops recording is not stored in the register, unless
                        it was the result of a mapping)  {Vi: no recording}


                                                        *@*
@{0-9a-z".=*}           Execute the contents of register {0-9a-z".=*} [count]
                        times.  Note that register '%' (name of the current
                        file) and '#' (name of the alternate file) cannot be
                        used.  For "@=" you are prompted to enter an
                        expression.  The result of the expression is then
                        executed.  See also |@:|.  {Vi: only named registers}

Typing q starts macro recording, and the recording stops when the user hits q again.

As Joey Adams mentioned, to disable recording, add the following line to .vimrc in your home directory:

map q <Nop>

It sounds like you have macro recording turned on. To shut it off, press q.

Refer to ":help recording" for further information.

Related links:

smr's blog: vim :: recording

Vi and Vim Macro Tutorial: How To Record and Play

As others have said, it's macro recording, and you turn it off with q. Here's a nice article about how-to and why it's useful.

It means you're in "record macro" mode. This mode is entered by typing q followed by a register name, and can be exited by typing q again.