$('#abc span').text('baa baa black sheep');
$('#abc span').html('baa baa <strong>black sheep</strong>');
text() if just text content. html() if it contains, well, html content.
$('#abc span').text('baa baa black sheep');
$('#abc span').html('baa baa <strong>black sheep</strong>');
text() if just text content. html() if it contains, well, html content.