Ukraine is two different countries, and has been since independence.

Note: I have written about the modern reasons for this conflict at length as a neutral standpoint, including the reasons leading up to and the history behind it and have posted a link at the bottom of this answer if you are interested. This answer is going to look at the demographics.

Ukraine is essentially a sociology lesson. I want to point out a few key demo-graphical maps that will support my premise that this is not a country of solidarity fighting an evil tyrant, but one of a long history of division. This answer will consist of a series of demographics with a little commentary. You will see by the end what the major source of conflict is. This will be a long answer.

I want to start of with this map to give some historical context.

A state, originally controlled by Soviet Union. Through a process of de-centralization of a huge nation for administration purposes, Ukraine republic was created by tacking on proximate lands in order to help with this administration. You will notice specifically the land added by Lenin in 1922, formerly known as Novorossia, and Crimea which was added later.

Lets start with some Political demographic maps

In 1991 Ukraine declared independence, along with Crimea…

The 1994 Presidential election

1998 Parliamentary elections

2004 Presidential Election

2007 Parliament Elections

2010 Presidential Election

I could keep going but you see the pattern? Politically this is a country divided. I want to add some more to emphasis this point…

This is the 2014 voting turnout, after the US coup. 2/3 of the pro-Russian areas boycotted the election.

Linguistics…

Ethno-linguisics

Linguistics

Support for Russian as a state language

Social Media use of language, Blue is Russian

Ethnicity

Religion

Findings:

So as you can see there is a deep division here. The reasons for this division stem back a few centuries and have also been impact by separate borders and cultural influence since then. This has created a definite rift, a separation of culture.

As I have said both sides of this rift are Ukrainian, but they both have very different ideas of what this means.

The west and centre, very pro-EU, look to the future, to new opportunities, to closer ties with EU and US, individualism, Speak Ukrainian

The south and east, very pro-Russian, look to the past, to tradition and culture, ties to Russia, to history and state, Speak Russian

The understanding of this division is important to understand the reasons why Russia is invading the Ukraine. It is a battle of the east vs west. And for a more political analysis I recommend you viewing my answer below.

My view:

Important source: