All will get executed and On first Called first run basis!!
<div id="target"></div>
<script>
$(document).ready(function(){
jQuery('#target').append('target edit 1<br>');
});
$(document).ready(function(){
jQuery('#target').append('target edit 2<br>');
});
$(document).ready(function(){
jQuery('#target').append('target edit 3<br>');
});
</script>
Demo As you can see they do not replace each other
Also one thing i would like to mention
in place of this
$(document).ready(function(){});
you can use this shortcut
jQuery(function(){
//dom ready codes
});