What is a key characteristic of a simplex radio system?

A key characteristic of a simplex radio system is that one party transmits while the other can only receive. This means that communication occurs in only one direction at any given time. In a simplex system, if one person is speaking or sending information, the other individual must wait until the transmission is complete before they can respond. This is in contrast to duplex systems, where both parties can talk and listen simultaneously, facilitating a more interactive conversation. Simplex systems are often used in situations where clear, one-way communication is sufficient, such as in certain broadcasting applications or in emergency situations where information needs to be shared quickly without the need for feedback.