A 13 inch notebook-style laptop created by HP in December 2011 and identified by model: Folio 13t-1000 (product number A4A71AV). Its dimensions are 12.54in (31.9 cm) x 8.67in (22cm) x 0.7in (1.8 cm) and its weight is 3.3lb (1.5kg).
There is either water damage or the liquid crystal display (LCD) is damaged. You will most likely need to replace the screen. Please follow the screen replacement guide.