What Are Histsize, Histfilesize, Histsize in Linux
All of these are shell enviroment varibales that determines the location and size of your current shell history.
Indicates the history file, that stores your shell commands.
Indicates the size of your history file, meaning how many command/events it can store. By defauat
zsh only sets in to 30, while not setting the
HITFILE at all, meaning no history is persisted.
Indicates the size of your current history session; how many commands from your history file can be loaded into your shell's memory in a session.