What is Karakamsa?
Karakamsa is the Navamsa sign of your Atmakaraka planet. Navamsa sign is the sign in which your Atmakaraka planet sits in the Navamsa chart.
What is the Swamsa chart?
Swamsa chart is the derivative chart made by rearranging your navamsa chart planets and their house positions as per Karakamsa lagna.
Essentially, when the Karakamsa sign is taken Lagna and your Navamsa chart is recast the chart we get is called the Karamsa chart.
What is Karakamsa lagna?
When your birth chart is recast and lagna or the 1st house is taken as your Karamasa sign, we get Karakmsa lagna.
What is Swamsa lagna?
When your Navamsa chart is recast and lagna or the 1st house is taken as your Karamasa sign, we get Swamsa lagna.
What is the role of Atmakaraka in the Karakamsa and Swamsa charts?
The concept of the Karakamsa and Swamsa chart is based on your Atmakaraka planet's Navamsa position.
What is the difference between Karakamsa and Swamsa charts?
Similarity:
Both charts have the same lagna signs. This sign is the sign of your Atmakaraka planet in the Navamsa chart.
Difference:
The planets in the Karakamsa chart reflect the planetary positions of your Birth chart or D1 chart.
The planets in the Swamsa chart reflect the planetary positions of the Navamsa chart or D9 chart.
If it is still difficult to understand you can follow this link. Making Karakamsa and Swamsa charts.