Can BASH execute commands on a remote server when the commands are embedded in shell

I want to log into a remote server transfer over a new config and then backup the existing config, replace with the new config.
I am not sure if I can do this with BASH scripting.
I have set up password less login by adding my public key to authorized_keys file, it works.
I am a little bewildered about whether I can execute commands on the remote server from within my BASH script.
I am thinking that It would be necessary to use expect. I have looked at expect and am not sure I want to go there.

I currently have
# ./copy_to_server httpd.conf.new /etc/httpd/conf/ 192.168.1.100
#/bin/bash
FILE1=$1
FILE2=$2
FILE3=$3
FILE4=$4
FILE5=$5
FILE6=$6

if [ ! -f "$FILE3" ]; then
scp $FILE1 $FILE3:$FILE2
else
echo "$FILE3 is not up"
fi

##########
So the file is on the remote server, now I want to move around some exsting files.

Now I am unsure how to set up to check for the existing httpd.conf and move it around on the remote server using BASH.
[ -f /etc/httpd/conf/httpd.conf ]
mv /etc/httpd/conf/httpd.conf /etc/httpd/conf/httpd.conf.bk_up
mv /etc/httpd/conf/httpd.conf.new /etc/httpd/conf/httpd.conf

And then log off

Can BASH do this on its own?

I thought that one way around this would be to create a cron job to check /etc/httpd/conf/ dir for a new file
when it finds httpd.conf.new it could move over the old and move in the new.

So now I am curious is executing multiple commands on a remote server via bash possible? and then logging off.

Any suggestions are appreciated.

You should start reading about ssh.