TWRP is a custom recovery for the Samsung Galaxy Tab 10.1 tablet. There are two variants of the this recovery as there are two versions of the tab – the P7500 (3G only) and P7510 (Wifi only version).
By installing recovery, you will be able to flash all sorts of hack on to the tablet, including ability to root your Tab 10.1 tablet and install custom firmware. Since Samsung has not churned any ROM after the official ICS for Galaxy Tab 10.1, it makes perfect sense to install TWRP recovery on the P7500 / P7510 and get the latest version of android unofficially.
Download links are given below.