This is a descendancy view example as found in FamilySearch. In this view, the "ancestor" is in the top left position. The spouse shows just below the man and the children of that spouse will show in the layers beneath. If there is a 2nd or more spouse, then they would show below the first spouse layers.
The icons to the right of the individuals represent things such Record Hints being available, or Research Suggestions, etc. As you explore the tree, you will find prior generations that end before recent times. Those lines are considered "dead end" lines where there is no FamilySearch information on them. Perhaps the end of line person had died early or didn't get married, therefore there would be no posterity. These dead end lines are great opportunities to explore further and oftentimes add more posterity to that line.
