[Xperia Z3 Q&A, Help & Troubleshooting] Jkay7:
Hello everybody, as not only in this subthread I see many questions being repeated I thought it could be nice to have an explanation for most of them. Please feel free to add answers! Questions are sorted into:

General

Root

Recovery

Xposed

Bootloader

Rom

General

Q: Which specs does my phone have?

A: Have a look at gsmarena.com, they provide splendid information to all devices.

Q: Where is the difference between (e.g.) D6603 and D6633?

A: The Xperia Z3 series is mainly divided into: Internationally available (e.g. D6603), Dual Sim (D6633, D6683), and branded (D6616). While the first group covery most internationally used frequency bands, the branded ones offer LTE support for T-Mobile and Verizon in the US. The disadvantage is that it is harder to develop for the latter.

Q: How do I seek support for a questions regarding xy?

A: If you have flashed something specific, ask in the thread you got the link from or where it originates. If you have more general questions, ask here or here. Note that many questions have already been asked, so please use the search function before asking a new question.

Q: I read up a little on various flashing related stuff and saw flashtool was mentioned. What is it? How do I get it to work?

A: Flashtool is a tool created by [MENTION=2807379]Androxyde[/MENTION] and it allows us to flash every file that we have in the .ftf format to our phones. While most of its steps are explained here, it is to note that if you use Windows 8 or higher, you may have to take an additional step to install the correct drivers for your phone. Look here for help on that.

Root

Q: What is root?

A: Root enables you to have more in depth access to your system. If you don't know what it is and want to aquire it, first inform yourself, for example here and find out what advantages it could give you as well as disadvantages and consider if it suits you. Never forget: Your warranty will be voided! While you can get it back, it might be quite some trouble if you're not somewhat experienced. On the other hand, people are always eager to help. If you don't try, you won't find out ;) .

Q: How can I root my device?

A: There are two possible methods it root your device, one being way more risky than the other.

Method 1: Downgrade to 4.4.4 (if you are not already there), then use giefroot, get a recovery and flash a pre-rooted updated ROM. Sounds complicated? Thanks to [MENTION=2731409]G-FACE[/MENTION] it is not! Look here to see how to root and install recovery on your handset!

Method 2: Downgrade to 5.0.2 and use Kingroot. This method is not recommended at all as it sends your IMEI, so your unique identification number to a Chinese IP address without knowledge who the receiver is. While it is possible, I would definitely recommend the first method.

Q: Help! I messed up on the way there!

A: Ask in the appropriate thread (depending on in which step you messed up), there are always people helping out! Generally speaking, flashtool will be one of your biggest companions. If you have questions regarding that, look at the prior section.

Recovery

Q: What is a recovery?

A: A custom recovery is either TWRP, Philz or CWM (different versions), which allows you to install .zip files onto your phone on the go, without using your PC.

Q: How do I get it?

A: Please refer here.

Q: Which of the three (CWM, Philz, TWRP) is favourable to do xy?

A: To be honest, it depends. While most of the time you won't use CWM, it is up to you to use Philz or TWRP. Note however, that some Roms or wipes may require a specific one of the two. Always refer to the OP of your file source. If it states you should use a specific recovery, do so, as you may encounter problems if you do not.

Xposed

Q:What is Xposed? What can you do with it?

A:Xposed advanced framework is an awsome tool created by [MENTION=4419114]rovo89[/MENTION] and helps you to easily mod your phone with tons of modules! For example you can blur your system UI, control which apps boot on start, or mod your phone to infinity. These are just few examples, I for my part use 13 xposed modules at the moment to get what I want from my device.

Q:Where do I get it?

A:Download it here if you're on LP or MM. Use the arm version, e.g. xposed-v79-sdk22-arm.zip

Now we have already learned the basics, so let's go a little further :)

Bootloader

Q:What is a bootloader?

A:

Refer here for further explanation.

Q:Why do I need to unlock it for a few Roms?

A:This is due to them using a different kernel, which would not work with a locked bootloader.

Q:I want Rom xy now, how do I unlock my bootloader??

A:Sony makes it a little easier than some other companies do, so have a look here. Note: Your warranty will be voided and you will lose your DRM keys!

Q:What are DRM keys? What is the TA partition?

A:As mentioned, unlocking your bootloader will wipe your DRM keys. These are unique keys generated by Sony to enable your access to some Sony-specific things. These include but are not limited to image capturing & viewing enhancements and access to PSN. The TA partition is the part of your phone where these keys along with your IMEI is stored. Before unlocking your bootloader you should backup your TA partition. How to do so? Have a look here.

Q:Help! I messed up/unlocked my bootloader without backing up my DRM keys.

A:I'm sorry to hear that. While you will not be able to get back your warranty, you can get back most of the functions. Look here for help.

Roms

Q:What are Roms?

A:To make it short: They are your OS, so your system that you're running on.

Q:What differences are there?

A:While we have many people use plain stock Roms, many here at xda favour modified Roms, be it to include Root or Xposed, or to go further by unlocking the bootloader (look prior topic) to flash Roms not based on stock, such as Cyanogenmod.

Q:How do I install Rom xy?

A:As long as you have it as a .zip file use your recovery, if its a .ftf file use flashtool.

Q:Where do I find (stock) Roms?

A:Luckily, there are collection threads for Roms here. Please refer here for pre-rooted stock Roms. If you want to reset your phone to its original state, use XperiFirm, it will help you download the .ftf for your phone!

Any further questions? Anything I missed? Please write it down below, I will add more Q&A's as we go :)

Feel free to link to this thread if one of these questions is repeated over and over in your thread!

It took me quite a while to organise this thing so please consider pressing "Thanks" if this post was helpful. :)