Colonial Space was made up of many more planets then the Twelve Colonies located in the Cyrannus System.
(Note: The Cyrannus System consists of a Triple star cluster with thirty four planets (of which twelve planets are habitable) in orbit around them.)
The Inner Worlds of the Cyrannus System are Caprica, Sagitaria and Virgon. These three have the most temperate and diverse climates and consequently developed the largest populations.
The Outer Worlds, Aries, Canceria, Taura, Gemoni, Leo, Libra, Scorpio, Aquaria and Piscon, tended to have less diverse climates and are more subject to extremes. Though they are still well within acceptable human living conditions.

Taken together, these twelve planets were considered the ‘Primaries’ or the ‘Home Worlds.’ ‘The Twelve’ were each different in climate and development, and population density. Though they all shared access to common technologies, not all of them utilised the technology to the same extent or in the same ways. For example, Caprica was one of the most technically developed and most densely populated of the Twelve. Its population was pushing fourteen billion at the time of Cymtar. Aquaria, though a heavy user of technology, was a much less densely populated planet (overall) with a population of about two billion.

Many other planets were found and settled by the Colonials. Some planets were heavily developed and had populations in the millions others had only a handful of people living on them. In general they fall into three broad categories.

There were another forty ‘Principal Colonies.’ These were well settled and developed planets, usually with populations from 50,000 up to a several million. They had established cities, industrial centers and first class space ports where ship repairs and some construction were possible.
A few of these planets, like Borella, had a human population living there when the Colonials first arrived. (Borellian Nomen.) Others were uninhabited and undeveloped. Life on these planets was little different then living on one of the Twelve. One might lack access to the latest fashions and the newest gadgets, but there were always ships arriving and departing and culture was not far beyond the ‘cutting edge.’

Additionally there was another seventy or eighty ‘Minor Colonies.’ A Minor Colony generally had a population of 5,000 to 50,000. There were usually only a few large settlements and though the colony often had some industrial capacity this was limited to a specialization oriented around the colony’s primary occupation. In most cases this was large scale Agricultural production or some type of mining or mineral extraction. These colonies had space ports able to handle the shipping of the colony product and capable of minor repairs and refueling, but little else. These colonies were all ‘Registered’ and recognised settlements, benefiting from, and contributing to, the Colonial Government as a whole.
Life on these colonies tended to run at a slower pace. Technology, fashion, news were always behind the trend. Not that living standards were harsh or difficult, no one starved, no one died from want of medical care, ships arrived and departed at regular intervals (though you might have had to wait to get one bound for where you want to go) and most of the luxuries of life were available, eventually.

Then there were an unknown number of ‘Stations’ and private ‘Settlements.’ These small colonies, often referred to as ‘Frontier Colonies’ were scattered along the edges of, and beyond, officially recognised Colonial Space. Population can range from a mere handful to several thousand.
Some of these settlements, like the Prison Colonies, were officially sanctioned and listed. Others were established privately, by corporations seeking to exploit some local resource, or religious or social groups seeking to escape the culture of the Inner Worlds. Others were built by explorers, extended families, shipwreck survivors, fugitives, pirates and various drop out groups. In most cases these colonies are Agricultural in purpose (though the corporate ones were often mining or specialised industrial) as a survival necessity. Most of the planets are marginal at best and survival is usually a struggle to some degree. Crop failure can mean starvation. Injuries, beyond a certain level, can mean death or disfigurement, ships rarely appear (perhaps a few times a yahren if that) and survival is often a matter of ingenuity.
Many, if not most, of these settlements never appeared on the Colonial charts. This was generally deliberate on the part of the founders. With the exception of some of the corporate centers, (and ship wrecks) the people who set these up did so to escape Colonial scrutiny and authority. Though common speech refers to these settlements as ‘colonies’ the Colonial Government and the Colonial Military designate them ‘Settlements’ for agricultural/population centers, or ‘Stations’ for industrial centers and mines. The reason for this is that the term ‘Colony’ has a certain legal significance and implies the the inhabitants are tax paying, voting, legal citizens.

Officially, the Colonial Government accepted responsibility for defending ANY human settlement from the Cylons, pirates and other aggression. In fact the policy was that any species who asked for help against the Cylons would receive it.
This policy was incorporated into the Treaty of Delphi which was signed by the Delphian Empress and the Council of Twelve. As a result of this the Colonial and Delphian Fleets would render aid to any inhabited settlement under attack or pressure by Cylons, pirates or other aggressors.