A "call" is a communication method where one person contacts another using a telephone or similar device. This can be done through traditional landlines or mobile phones, and it allows for real-time conversation. Calls can be either voice-only or include video, depending on the technology used. There are different types of calls, such as voice calls, video calls, and conference calls. Voice calls involve only audio, while video calls allow participants to see each other. Conference calls enable multiple people to join the same conversation, making them useful for meetings and group discussions.