A Smartphone is a mobile computer (Mobile referring to being portable). All Smartphones are cellular devices that come with an Operating System (OS). While most people associate Smartphones with touch screens, this is always not the case. Some Feature Phones (phones with buttons) have Operating Systems which basically makes them Smartphones.
They are two major Operating Sytems in the Smartphone industry. iOS Operating System and Android Operating System. iOS Operating System was created by Apple and only used in Apple product such as iPhones and iPads. Android was created by Google and operates about 99% of Smartphones that are not made by Apple.
G in 4G stands for generation, with 4G standing for Fourth Generation of Mobile Data. LTE stands for 'Long Term Evolution'. LTE refers to the improvement of Wireless broadband speeds in meeting increasing demand. 4G and LTE are totally different things. A 4G network requires a Smartphones to have a peak of at least 100 Mbs (megabits per second). LTE refers to the path taken by networks to archive 4G capability. The network regulating body decided to give the '4G' name to technologies that pursue the 4G standard.
Recent advancement in the network industry is the LTE-A. LTE-A stands for Long Term Evolution Advanced. LTE-A allows faster speeds and stability than LTE. LTE-A is backward compatible which allows connection to multiple networks in the vicinity allowing you to download from different networks at the same time.
Best Camera Smartphones.
Cheap Camera Smartphones are the Tecno Camon Series, Huawei Y7 Prime (2018) and Oppo A series.
Middle-Range Camera Smartphones are Tecno Phantom Series, Oppo F series and Xiaomi Mi Series.
High-End Camera Smartphones are all iPhones, Samsung Galaxy S series, Huawei Honor Series, Huawei Mate Series and Samsung Galaxy Note series.