Caution! Use these charts carefully. The testing strategy differs a lot between countries so the number of diagnosed cases is not a reliable way of comparing the spread of the virus between different countries. What you can do though is for example to use the charts to see whether or not a country seems to have reached a peak, but realize that testing strategy might also change within a country over time so even that might be unreliable.
The curves start on the day that the country had 100 cases, or 40 cases per million inhabitants. The graph showing new cases per day uses a 7-day rolling average.
As mentioned in the first section it is difficult to compare cases between countries but doing it within Sweden should be OK as the testing strategy is somewhat similar in all regions. Use these graphs to understand at what stage your particular region is. You can use the third graph to see if the curve has started to level off which we should expect to see in the graph of cases a few weeks before the graph of deaths. These graphs start on the day that the region had 20 cases, or 40 cases per million inhabitants.
Every day new official numbers are presented by Folkhälsomyndigheten and on the news but often without the proper context. On this site I try to present current data on Covid-19 that is interesting from a Swedish perspective, using charts that provide context and gives us an idea about what the current situation actually looks like.
Please carefully read the introductory text of the charts to better understand what I am trying to show and why. Also, note that several of the charts use a logarithmic scale by default, making an exponential increase look like a straight line. So always keep an eye on the y-axis and switch between the linear / logarithmic view to get a better feel for the data. To better understand exponential growth, have a look at the videos at the bottom of the page.