Samsung recently launched its S21 series on 29 January 2021 namely, Galaxy S21, Galaxy S21 Plus and Galaxy S21 Ultra. All of these devices run on Android 11 with One UI 3.1 skin on top. Two years back on August 2019, Samsung released Galaxy Note10 series which included Android 9 (Pie) by default but later to Android 10 and now upgradable to Android 11, One UI 3.0.
Samsung is rolling out February 2021 security patch in the USA to these smartphones series while their predecessors, Galaxy S20 and the Note20 models already bagged this update.
The Galaxy S21 update carries G991USQU1AUAG firmware version that weighs approximately 305 MB in size. On the other hand, Samsung Galaxy Note10 series are pumped by firmware versions N970USQS5EUA1, N975USQS5EUA1 and N976VVRS5EUA1 for Galaxy Note 10, Note 10+ and Note 10 Ultra, sequentially.
Apart from the new security patch, the update also brings some add-on features such as improvement in the camera, fixes some minor Bugs, improve and enhance the system and device stability. As usual, the update is rolling out in a phased manner so the owner either has to wait or check it manually via phone Settings > Software Update.