Difference between Dual SIM, Hybrid Dual SIM and eSIM card

What is the difference when mobile phone supports Dual SIM, Hybrid Dual SIM or eSIM card ? Can I use two SIM cards in phone in each of these cases ?

You can use 2 SIM cards in all those cases at certain circumstances:

Dual SIM slot allows you to insert and use two SIM cards with your phone.

Hybrid Dual SIM slot allows you to insert and use one SIM card + another SIM card or memory card, so you have to decide, if you will use two SIM cards or one SIM card and one memory card.

eSIM card meaning embedded SIM card is a technology when physical SIM card is not necessary. It is embedded directly into a device. The user profile can be downloaded to eSIM card. If needed it can be later rewrited or removed.

The using of eSIM card is now available only in some new mobile phones like Samsung Galaxy Note 20 or iPhone 11. These phones allow you to use standard plastic SIM card or eSIM card with downloaded profile, if your mobile operator supports it.