what window style is this?

Folks. hello.... anyone out there?

i am hoping that a large number have come across to WWF and have retained their usernames from Renovate Forum. always nice to know with whom one is conversing.

we are reformatting a large room into two bedrooms for my boys. have to put in some new widows as the current crappy old one will be across the new wall once its built. can anyone tell me what the style is of the aluminium sliding windows that have the slider at top and a fixed pane below?

Bradnam's merely calls them sliding windows (The Different Types of Windows | Bradnam's Windows & Doors) but i thought they had a more specific name. the type is the same as in the picture shown for sliding windows on the bradnam site.