There are several different point-of-sale (POS) systems. A point-of-sale system is where the transaction takes place between the customer and the company that is providing the service or that is selling the product. POS systems are used in every transaction that is made whether that is online, in-store with a card, or cash. Other features of most POS systems include inventory and customer management. These systems can keep track of all the products that are on the shelves, as well as the customer and the whole customer profile.
Mobile POS is just that, mobile. It is when the transaction is made on a mobile device such as a tablet or smartphone, at the Apple store every employee has a mobile point of sale system. These are becoming more popular because any employee can check out any customer, it reduces waiting times because there are more “registers”. It also makes it easier for a company to offer bonuses for sales because of the IP address on the device. When there is a single form of checking out it requires more steps for the companies that offer bonuses or incentives. These mobile POS systems often have a card reader and a receipt printer on them so it’s the same experience as the traditional way of checking out but it's faster and more convenient for the customer.
Terminal Point of Sale systems
Terminal POS systems are used when a credit/debit card goes into the reader. So for example at the gas pump or at the store when they have you insert the card. The terminal can be cloud-based, but most of the time they are still attached to the internet. These systems often include bar scanners, cash draws, and tablet stands. Most are made for fairly simple business, but some can handle complex orders and processes.
Online Point of Sale systems
The online point of sale is better for small businesses and businesses with a high number of sales like a museum or a café. This system makes using a standard printer possible, which is really convenient for small businesses with high numbers of sales.
Self-service Point of Sale
This is the point-of-sale system where there are self-service kiosks put out to eliminate the use of human interaction. This takes away the business having to pay an employee to take orders. This would work great for companies such as Mcdonald's and Burger King because they make food from a menu and people get to customize their food within reason. Another place that commonly uses a self-service POS system is grocery stores because they sell the same things all year round and they scan a bar code that is attached to the product. These are also good for patients to check in for their doctor's appointments, it allows the system to check them in to let the nurse know that they are ready in the waiting room.
Multi-channel Point of Sale systems
Multichannel is the best for when your company sells products on different platforms like online and brick-and-mortar. This system brings all the sales to one place and creates an easy interface to see all the statistics in one place.
Open-source Point of Sale systems
With an open-source system, businesses are allowed to customize their POS system to do exactly what they want it to. This system can get quite pricy and is best for large companies who do a lot of business on multiple platforms. With this POS you will need to get a software engineer to build it and will have to do all managing of the system and updates in-house. So even after it is built it is still a good idea to have at least one person if not a team of people to actively manage this system to make sure it is secure, if it can get hacked then it creates a huge security risk and is putting your customers at risk.
https://www.business.com/articles/types-of-pos-systems/