Each card on a board represents a task and is marked by the same color as the task it corresponds to. On it you can see:
1 Task name
2 Its start date
3 Who it is assigned to
4 Task path
From the card, it is also possible to switch to Task settings 5 in general, or Comments on the task 6 and Attached files 7, in particular.
For a quick overview of the task description, hover the cursor over the info icon 8 in the bottom right corner.
You can drag & drop cards between columns based on the categories they are grouped by. Moreover, you can hide columns you do not need to see at the moment by hovering over the column name and clicking on a minus sign, or bring them back by clicking on the plus sign near the column name.