To check history of the commands which has been executed.
[root@server ~]# history
1 whoami
2 clear
3 ls
4 whoaami
5 ls -ltr
6 top -c
To check last 5 commands in history use history 5
[root@server ~]# history 5
92 clear
93 whoami
94 top -c
95 history
96 history 5
To clear history use history -c
[root@server ~]# history -c
[root@server ~]#
[root@server ~]# history
1 history
To delete a particular command in history use history -d
[root@server ~]# history 5
1 history
2 whoami
3 clear
4 hisry 5
5 history 5
here I'm deleting the command which I fired at 4th Number
[root@server ~]# history -d 4
[root@server ~]# history
1 history
2 whoami
3 clear
4 history 5
5 history -d 4
6 history
To run a command at particular number in history you can use ! followed by the number. Example you want to run the command at number 2 the run !2
[root@server ~]# !2
whoami
root