With a local list, any changes made to the history will only affect the current TCC tab window. They will not be visible in other tabs or other copies of TCC.
With a global list, all TCC windows will share the same history, and any changes made to the history in one copy (e.g., by executing commands from the prompt) will affect all other copies. Global lists are the default.
If you select a global history list for TCC, you can share the history among all TCC sessions running concurrently. When you close all of the TCC sessions, the memory for the global history list is released, and a new, empty history list is created the next time you start TCC.
If you want the histories to be retained in memory even when no TCC session is running, see the SHRALIAS command, which retains the global alias, user-defined function, command history, and directory history lists. SHRALIAS retains the lists in memory, but cannot preserve it when Windows itself is shut down or the user logs out. To save your histories for the next restart of Windows, you must store them in a file and reload them after the system restarts. For details on how to do so, see the HISTORY and DIRHISTORY commands.