Why do you slide for some calls but tap for others on your iPhone

Your iPhone requires sliding for some calls but others can be answered by a quick tap. Your phone presents a logical approach to answering calls through either sliding or tapping.
When You Slide to Answer
Users must glide to answer phone calls from a locked iPhone according to Apple's requirement. Your phone will not answer calls automatically when it is inside your pocket or bag through this protection.
When You Tap to Answer
When your iPhone is unlocked you can easily use the tap-to-answer feature. There is no requirement for additional touch protection because the phone remains in active use.
Bonus: What About Declining Calls?
The locked screen interface excludes decline buttons so you must use the power button twice to end a call.
You will see buttons for Answer and Decline on screens that are unlocked.
Through its smart design Apple protects users from answering or declining calls mistakenly.