 The Shading Editor is a node editor specifically used for editing shader nodes. This may seem intimidating at first, but nodes are very powerful tools that allow for flexible customization. Keep in mind that many of the basic functions of how to navigate the shader editor will also apply to the compositor, Blender's other node editor. So, first things first, navigating in the node editors is very similar to navigation in the viewport. Middle click drag to pan your view and scroll to zoom in and out. Moving your nodes is simple as you can simply left click drag a node over. However, you can also use the gr and s hotkeys to grab, rotate and scale your nodes respectively. Now that we got that out of the way, let's explain how nodes work. There is typically a starting node or several starting nodes that then combine using other nodes until they all converge into a single ending point, which is the output. As you can see here, the default material already has a shader node and an output node. In this case, the shader node is a starting point and the output node is our ending point. It should be noted that it is possible to have more than one output node, but only one output can be displayed at a time. This depends on which one was last selected, which will highlight the top of the node red. So let's pretend we want to add an image texture to our shader, but maybe we also want to add a gradient to that texture at the same time. Simply navigate to the image file you want to use in the file browser panel. Left click drag your texture file into the node editor. This will create an image texture node for you. You can then left click drag the color output of this node into the base color input of our shader. You might notice that the yellow circular connection receivers are the same color as each other, telling you that they are indeed the same data type. Another way to quickly connect two nodes is to select them both, go to the node menu, and select make links. This forms a connection of matching type between the two nodes, prioritizing the uppermost connection slots. For hotkey users, simply press F as in fill to do the same thing. Now this looks great, but I did say I wanted to add a gradient to this texture. So let's go ahead and go into the add menu above the shader editor, and go to textures gradient texture. For hotkey users, simply press shift A to access the add menu at any time. After you select a node from the add menu, you can right click to cancel the add or left click to confirm its placement. Let's put it to the side underneath our other texture we want to mix it with. Now that we have our gradient texture, we can test what it looks like by simply plugging it into our shader base color node. One way to do this is to move the outgoing connection from our image texture to stem from our gradient texture node instead. If you ever want to do this, simply control left click, drag the connection. This will allow you to pick up the outgoing connection and connect it to a different output source. Quick note, holding control is not necessary for picking up existing incoming connections. Let's go ahead and connect this now to our gradient texture output. As we can see, it is indeed a black and white gradient texture. Cool, now we can reconnect our image texture and figure out how to combine these two textures. Because these two outputs are color outputs, we want to manipulate these values with a color node of some sort. This is a great way to get hints on what nodes to use in certain situations. Let's go back into our add menu and take a look under the color category. We see that there is a node called mixRGB. Well, we do want to mix our textures in some way, so I think it sounds like something we want. Let's add it in. You might notice that before you confirm the node's placement, if you hover over an existing connection, it will highlight that connection. Placing the node over an existing highlighted connection will automatically sandwich it between the two connected nodes. Let's do this for our new mixRGB node. Now that we have our mix node connected, you'll see that our texture has gone a bit gray. That's because the mix node currently is using a default gray color as the secondary input to mix our texture with. Let's simply connect our gradient texture node into the bottom half of this mix editor to replace the default gray color. As you can see, we're already getting there. The gradient texture is now mixing with our image texture. Okay, but let's say I want to quickly compare the difference between having the gradient mixed and having nothing mixed at all. To do that, Blender allows you to mute nodes. Simply select a node and right-click for the context menu. Then select toggle node mute. You can then select it again to unmute the node. For hockey users, simply press M as in mute to do the same thing. As you can see, muting a node allows the connection to bypass the effects of the node. The gradient is no longer being shown. Keep in mind that muting a node will choose the uppermost input to bypass as the output, ignoring all other inputs. So let's say I toggle between my options, gradient or no gradient, and I decide that I prefer it with no gradient at all. Well, for that, we might as well delete the mix node. There are a few ways to delete a node. Most forms of deletion work here in the same way as they do in the 3D viewport. Let's select the mix node and press X or the delete key to delete it. However, as you can see, this forces us to manually reconnect the image texture node back to our shader node. This is a bit tedious, but luckily there's a way to avoid it. Let's go ahead and hit undo until we have our mix node back. Now, we can right click our mix node and select delete with reconnect. As you can see, the mix node has been deleted but keeps the connection intact. For hotkey users, you can simply press control X. Another trick you can use is to simply alt click drag the node away. This will disconnect the node without disrupting the existing connection. Wonderful! Now my shader looks exactly the way I want it. Or does it? What if I changed my mind and decided that I wanted no image texture at all? How do we completely disconnect our image texture from our shader? One way we can do that is to simply click and drag the endpoint of the connection off of our shader node and release. This is intuitive but can be very tedious. A faster way is to cut the connections with the links cut tool. You can select the links cut tool in the quick tools menu on the left. Once you select it, you can use this tool by left click dragging over the line of a connection or connections. This will break any intersecting connections immediately. For hotkey users, simply hold control and right click drag. I hope this gives you a good introduction on how to navigate the node editors as well as how to manipulate nodes.