There are 4 different structures of adventure design. Each individual session is a mixture of these styles. It is neigh impossible to create an adventure not using a mixture of the below.
The first is the Linear Structure, or "flowchart style". Because it says linear does not mean that there are no options or choices. Linear simply refers to the progression. You are in one place and have a limited number of options. This can refer to the classic dungeon (a literal flowchart if there ever was one) but also to a scene based game (because each scene has a number of different outcomes that it can lead to).
This structure is visually represented by a flowchart - each box containing a reference to the information of what happens when it is reached.
The second is the Space Structure, or "sandbox style". This is quite literally a box which contains various objects. Each object could be a scene or a dungeon or an event depending on the type of game. It is primarily characterized the freedom of player choice. It could be an unexplored wilderness with different sites, a murder mystery with different subjects to talk to, or a trick room within a dungeon.
This structure is represented by a (sandbox) map - each item containing a reference to to the information of what each box contains.
The third is the Time Structure or "schedule style". This style simply means states will change depending on the time within the game. In the linear or space structure each scene is simply triggered by the players arriving at it - using the time structure allows you to have a city guard change shifts, or have someone not be at home because they are out working the fields. On a broader scale this means the bad guys have a plan and they will accomplish their goals at these times, or a PC can only recharge their magic items during a new moon.
This structure is represented by a schedule. I'm sure you're sensing a theme here. Each item on the list contains a time (or a time frame) and a reference to what occurs when that time is reached.
The fourth is the Power Structure, or "spiderweb style" or "node style". In this style each active source of influence (i.e person, faction, pet, diety, city, etc. Any possible thing that exerts an independent influence over events) is given a list of drives, desires and goals, and put into play with every other active source of influence. This could be factions in a static area (like a mega-dungeon, city, or countryside), individual people, or even gods. Each is then set loose to act as intelligent independent agents.
This structure is represented by a nodes, each connected (resembling a spiderweb). Each individual node contains the name of the influence source and a reference to their goals, drives, and desires. Their relationship with each other influence source is represented by a line drawn in a variety of styles (dashed, dotted, colors, double barred) indicating the relationship between the two entities.
None of these is meant to be used in isolation. I imagine the vast majority of you are already using many of these styles in play. Explicitly identifying these can let you more effectively run complex adventures swiftly and be prepared for unexpected player actions (for if you have all these in place - there is nothing they can do that you are not prepared for.)