paste vs cat vs awk demo

bash-4.2$ seq 5 > first_file

bash-4.2$ seq 6 10 > second_file

bash-4.2$ paste first_file second_file
1       6
2       7
3       8
4       9
5       10

bash-4.2$ cat first_file second_file
1
2
3
4
5
6
7
8
9
10

bash-4.2$ awk '1' first_file second_file
1
2
3
4
5
6
7
8
9
10