802.1X is a standard that enables the use of an AAA server in a domain environment by providing port-based network access control. 802.1X authenticates users or devices before granting them access to the network resources, and can also authorize them based on their roles or policies. 802.1X can work with different AAA protocols, such as RADIUS or TACACS+, to communicate with the AAA server.
References:
* CompTIA Network+ N10-008 Certification Study Guide, page 211
* CompTIA Network+ N10-008 Cert Guide, Deluxe Edition, page 382
* Configuring AAA Services - Cisco3

A captive portal is a web page that requires users to authenticate or accept terms of service before they can access the internet through a wireless access point. A captive portal can be used to control who can use the wireless network, limit the bandwidth or time of usage, or display advertisements or information. A captive portal is a common feature of public wireless networks, such as those in hotels, airports, cafes, or libraries. A captive portal can prevent unauthorized or malicious users from accessing the network or consuming network resources.
References: Public Wireless Access Points Definition | Law Insider