Constructor difference and HardwareSerial and SoftwareSerial difference

Hi, I have a few questions for my understanding

• what is the difference between : LoRa_E32 e32ttl100(2, 3,5,6,7); and LoRa_E32 e32ttl(2, 3,5,6,7); ?
• what is the difference between serial and hardware the interest of everyone?the most efficient method?

thank you :)