As someone who has (thankfully) never had to claim any sort of unemployment benefit, I’d say i’m a little bit of a novice on the subject. I was always under the impression that Universal Credit was a rebranding of Jobseekers Allowance, with the inclusion of several other benefits, but in fact a new style JSA additionally exists, and Universal Credit is more likely to be claimed by people actually working. From my understanding of the two:
Universal Credit can be claimed by anyone without any savings or assets worth more than £16,000, and struggling to make ends meet. There is no upper income limit. This means that you could be working 8 hours per day 5 days a week, but because you are on such a low income or have high essential outgoings (such as spending on children), you need the UC to top up your income. In such case, a condition of receiving the benefit would be to look for better paying work, with payment of UC going down gradually the more you earn.
The New Style JSA can only be claimed by anyone unemployed or working less than 16 hours per week with 2 years worth of National Insurance contributions. This is more suited to people who are in a better financial position (but still need day to day money and NI credits), and are likely to find work more quickly due to their track record.
I’m intrigued to find out more about the differences between the two, so please correct me if I’m wrong on any of the above.