What does Transactions involve? I'd like to have a more in-depth understanding of the business.

Hi, I'm currently on the financial services transactions graduate scheme and completed a summer internship with the team before joining permanently. What you achieve on your internship will depend on which specific department you apply to. See here for details on the options available: http://ukcareers.ey.com/graduates/our-programmes/graduate-programmes/transactions-gp
In the financial services scheme, you will experience multiple areas of the business e.g. spend time in both Transaction Support and V&BM, while in UKI you apply to one specific team.
As an example of the day-to-day work, if you were to choose transaction support it is likely that you would spend a number of weeks on the same project e.g. an IPO / a buy-side diligence, working with a core team to manipulate and analyse data to provide the client with key insights for the transaction. This will largely involve working in excel databooks and writing a report.
Let me know if there is a specific team within Transactions that you are interested in and I would be happy to give you more specific information on it.