Why are command aliases not remembered?

Question

linux

I made a couple of aliases for my convenience
, worked for a couple of days and then the system says - why are you bro? there is no such command..
Here are the aliases

alias ft0='service pure-ftpd stop'
alias ft1='service pure-ftpd start'
alias h='history'

There were no reboots (and if there were, would the aliases have to remain?)

Answer 1

As far as I know, aliases are reset when the session ends. They need to be written to a special file, for example, on CentOS this is .bashrc in the home folder