Very close and right you both are
slipstick and
mrlmmsguy.
It's the same in DAW's like Lmms and others etc.
I made a post to someone, where I explained, what
Mixing and Mastering is, a few months ago on this forum.
But I can't seem to find it.

So I'll try and explain it again, in simple laymans terms.
Mixing: is normally, when you put all of the cool Vst Instruments, Vst Synths and audio sample sounds
all together, in Lmms etc.
In other words, eg. you are mixing/putting all of the synths and sounds all together, in Lmms or any other Daw etc.
With some minor volume adjustments or other etc, as you make your melodies and put everything together etc.
Mastering: is when you try to make all of the synth sounds, instruments, audio files, Lmms internal plugins
and sounds, all fit in well together. And sound well together,
without hitting the red zone/cause clipping.
By using
equalizers,
limiters,
compressors (and hopefully they work

)etc.
And, doing
some manual volume reductions etc.
To make all of the instruments/sounds, sound clean and not sound too muddy, or cause any clipping/noise distortions,
in any of the instruments
FX channels,
especially the master channel.
And, to prevent all/some of the sounds, from drowning out, or overpowering other sounds, that you don't want drowned out.
Note: The master channel and other channels, are all auto set on
100 volume.
If any of them, especially the master channel, hit the
red zone, you might hear clipping/distortion.
Some people master, while making the melodies etc.
Others master, after they make all of the melodies and put everything together etc.
And some do it anyhow. Lol!
Your choice.
As
mrlmmsguy said, they do go hand in hand.
Hope that helps you guys.