The body scrolls while the header and footer stay fixed.
Terms and conditions typically live in a modal like this one. The content below repeats so you can see the scroll behaviour.
Section one. Lorem ipsum dolor sit amet, consectetur adipiscing elit. Nulla facilisi.
Section two. Integer posuere erat a ante venenatis dapibus posuere velit aliquet.
Section three. Cras mattis consectetur purus sit amet fermentum.
Section four. Aenean lacinia bibendum nulla sed consectetur.
Section five. Vestibulum id ligula porta felis euismod semper.
Section six. Donec ullamcorper nulla non metus auctor fringilla.
Section seven. Maecenas sed diam eget risus varius blandit sit amet non magna.
Section eight. Curabitur blandit tempus porttitor.