Use v to start characterwise visual mode.
Use V to start linewise visual mode.
Use Ctrl-v to start blockwise visual mode.

You can use motions to expand the visual area.
You can also use text objects to expand the visual area.

Just some of commands you can use in visual mode include:
~ - Switch case
c - Change
d - Delete
y - Yank
r - Replace
x - Delete
I - Insert
A - Append
J - Join
u - Make lowercase
U - Make uppercase
> - Shift right
< - Shift left

usa,Alabama,Montgomery
usa,Juneau,Alaska
usa,Phoenix,Arizona
usa,Little,Arkansas
usa,Sacramento,California
usa,Denver,Colorado
usa,Hartford,Connecticut
usa,Dover,Delaware
usa,Tallahassee,Florida
usa,Atlanta,Georgia

line 1: one
line 2: one,two
line 3: one,two,three
line 4: one,two,three,four
line 5: one,two,three,four,five
line 6: one,two,three,four
line 7: one,two,three
line 8: one,two
line 9: one

class Person
  def initialize(nick_name, birthdate, telephone, title)
    nick_name=nick_name
    birthdate=birthdate
    telephone=telephone
    title=title
  end
end

john.nick_name = "Happy"
john.birthdate = "4/4/1984"
john.telephone = "(555) 612-2000"
john.title = "Developer"

function make_slave_device_file () {
# Pass in slave device, slave device file, bond device.
local S_DEVICE=$1
local S_FILE=$2
local BOND_D=$3
echo "DEVICE=${S_DEVICE}" > $S_FILE
echo "BOOTPROTO=none" >> $S_FILE
echo "ONBOOT=yes" >> $S_FILE
echo "MASTER=${BOND_D}" >> $S_FILE
echo "SLAVE=yes" >> $S_FILE
echo "USERCTL=no" >> $S_FILE
echo "NM_CONTROLLED=no" >> $S_FILE
}

START:United States of America State Capital List
United States of America,Alabama,Montgomery
United States of America,Juneau,Alaska
United States of America,Phoenix,Arizona
United States of America,Little,Arkansas
United States of America,Sacramento,California
United States of America,Denver,Colorado
United States of America,Hartford,Connecticut
United States of America,Dover,Delaware
United States of America,Tallahassee,Florida
United States of America,Atlanta,Georgia
END:United States of America State Capital List

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Episode V:
The Empire Strikes Back
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