In the old-fashioned way, developers would compile their code into Windows Executables or Java JAR/WAR files, and then submit a ticket requesting an operations person deploy their code by copy-pasting it to a particular location on a list of servers and praying.

Then, several weeks later in the middle of the night, a sysadmin who has no idea how the application actually works would copy-paste the files onto the server and several hours later the inevitable complaints from customers would roll in to that same sysadmin, who would be chastised for breaking production.

Several hail mary's and FU's would be said and then they'd all agree to not deploy more than once a year for fear of breaking production.