Tera Term is a terminal emulator for controlling computers, network equipment, development boards, and other devices through a text session. It can open an SSH or Telnet connection over a network, talk to a local serial port, and replay a saved terminal log. Tera Term sends keystrokes or automated commands and displays the returned character stream. It does not add a graphical administration layer, repair a network route, or choose the correct serial settings for an attached device.
Network or serial
The New connection dialog separates TCP/IP sessions from serial sessions. A network session needs a host name or address and a selected protocol. An SSH session then authenticates the server and user, while Telnet sends terminal traffic without SSH’s encryption. A serial session selects a communication port that Windows currently exposes.
The terminal window can look similar after either connection, but the route differs. A failed network login will not respond to changes in the serial baud rate, and a missing serial port will not improve after changing an SSH cipher. Identify whether the target is reached through a network socket or a physical adapter before changing terminal behavior.
Serial parameters
A serial device expects matching values for speed, data bits, parity, stop bits, and flow control. Tera Term can open the port when some of those values are wrong, so a successful connection does not prove the session is configured correctly. Wrong settings commonly produce unreadable characters, missing output, or a prompt that stops responding after a burst of text.
Set the values from the device manual, not by guessing until text appears. Hardware and software flow control are different choices. Selecting a method the cable or device does not support can block transmission even when the receive side still displays startup messages. A USB-to-serial adapter can also return under a different port number after moving to another socket.
Verify the host
For SSH, Tera Term compares the server’s host key with its known-hosts record. The first connection presents an unknown fingerprint. Obtain the expected fingerprint through a trusted route and compare it before accepting. The account password authenticates the user after this step; it does not confirm that the remote machine is genuine.
A later mismatch deserves the same care. An administrator may have rebuilt the server or rotated its key, but an unexpected machine can also present a different key. Do not erase the stored entry simply to remove the warning. Confirm the new fingerprint first, then update the record when the change is legitimate.
Macros remember state
Tera Term Macro can open a connection, wait for particular terminal text, send a response, and continue through a repeated console task. It suits deterministic setup sequences and test equipment whose prompts remain stable. Text matching is literal enough that a changed prompt, translated message, or extra startup notice can leave the macro waiting at the wrong step.
Connection settings need equal precision. When a macro does not name the intended method, saved state can influence whether Tera Term attempts SSH, Telnet, or another route. A script written after an SSH session can therefore fail when it later expects plain Telnet behavior. Define the route and connection details explicitly, and stop on an unexpected prompt instead of sending later commands blindly.
Logs and replay
Session logging records the character stream for troubleshooting or an audit trail. Options control whether Tera Term appends to an existing file, writes binary content, adds timestamps, or includes the current screen buffer. A plain log can lose control sequences that matter to an exact replay, while a binary log can be difficult to read as ordinary text.
Logs can also capture passwords echoed by a device, tokens printed by a command, and configuration data shown on screen. Store and share them with the same care as the session itself. Replay reads captured data into a terminal window for later inspection; it does not reconnect to the device or prove that the current device still has the recorded state.
