Here are some categories which you should consider about before purchasing a smartphone:-
1. Camera -if you want camera for your good photo you should consider iPhone and mobile which contain Sony camera as we know Sony produce best camera.
2. Processor- this is most valuable category you should prefer before purchasing phone because it's the brain of the phone.
3. Storage- storage capacity is another thing you should consider according to your requirement.
4. battery- power storage is key aspect of phone right now because everyone needs good battery life.
5. Screen size- you should consider this category according to your demand as how friendly this phone can be in your hand and how big screen is your demand right now.
6. price- price can be main aspect if you want budget phone so decide what your range and how much you can spent.
7. Reliability and rating- you should consider this if you match the upper quality of the phone. You should consider this from famous online platform like amazon or flipkart or any rating website.
8. Screen quality- we can see the latest quality evolving technology like gorilla glass 5 is latest version you can consider.
9.earphone- earphone consideration is also major thing if you want plug in your do not consider new version of iPhone and new 1+ phone because they are not given plug option in their phone .
10.charger- charger and charging method is very important to new generation phone because everyone want fast charger so you consider fast charger.
11. Cable type - now days type c charging cable are popular and very good for reliability for future technology.
12. software- you should consider the company if you are purchasing android, the company should use latest version and available for new update quickly.
13. Sound quality-latest version of sound software should be used in phone is latest version and the hardware of sound should be latest like Dolby atom etc.
14. sensors- sensors what used in phone should be tested and approved by technology.
15. privacy- now day's privacy is very major thing for users because so many companies do not consider this thing.
16. Picture quality- it should also consider because if frame is low then usual then picture is appear good on screen .
17.mobile network range- some phone can have good quality but range of network that they catch is very low range so it become very difficult find range in our area that why some phone work properly in outstation but some privacy phone do not work properly.
18.sim card - sim card option is very considerable thing because some people want more than one sim card in phone ,please check phone feature before buy if phone have more than one some card with SD card or some phone have option for option for SD card in port of another sim card so beware of that.
Remark- (a)some phone are came with earphone some are not so buy with option what you want with . So many phones come with screen guard as well now days so you can consider this option also but it not that important. (b) Last but not the least before buy the phone make sure you buy good insurance for further safety.