How to Combine Two Text Files in Linux

In the course of work, I have received several redirected command output files from my colleague, and he asked me to combine all the files into one file and send it back. And I’m not in the mood to open all the files one by one to read the output and combine them into one file.So I have to find a way through which I can combine multiple text files into one, and then I can comfortably drink a cup of coffee.