# The words behind Tidix. Plain definitions of the terms the feature pages use, each with the features where you meet it. ## App uptime How long an app has been running. Tidix counts it from the start of the app's oldest process still running, helpers included. Used in: [App details](https://tidix.app/features/app-details) ## Bluetooth Classic The original form of Bluetooth, also called BR/EDR, built for steady links such as audio. A Classic device announces what it is through its [Class of Device](https://tidix.app/glossary#class-of-device). Used in: [Bluetooth](https://tidix.app/features/bluetooth) ## Bluetooth Low Energy (BLE) A power-saving form of Bluetooth, introduced with Bluetooth 4.0, for devices that send little data and must make a small battery last. A device can support Classic, Low Energy or both. Used in: [Bluetooth](https://tidix.app/features/bluetooth) ## Bundle identifier The unique reverse-DNS name a Mac app declares in its Info.plist, such as `com.apple.Safari`. Most of the app's preferences, containers and caches are named after it. Used in: [App details](https://tidix.app/features/app-details) ## Class of Device A code a Bluetooth Classic device sends to say what it is, such as a keyboard, headphones or a phone. Devices that use only Low Energy don't send one, so Tidix uses the type macOS reports for them. Used in: [Bluetooth](https://tidix.app/features/bluetooth) ## Efficiency cores The low-power cores of an Apple silicon chip, which macOS uses for background and lighter work. Tidix groups their tiles under Efficiency cores, with the group's average load. Used in: [Performance](https://tidix.app/features/performance) ## Helper process A separate process an app starts from inside its own bundle to do part of its work, such as rendering web pages. Activity Monitor lists each one on its own row; Tidix adds them up under their app. Used in: [App details](https://tidix.app/features/app-details) ## Hotspot temperature The hottest reading among a chip's temperature sensors at a given moment. Tidix's Thermals chart follows it: the hottest SoC sensor on Apple silicon, the hottest CPU or GPU sensor on an Intel Mac. Used in: [Performance](https://tidix.app/features/performance) ## Kernel extension A `.kext` bundle that loads code into the macOS kernel itself, the older way to add drivers and low-level features. Apple now steers developers to system extensions and DriverKit, and Tidix shows whether each third-party kext is loaded. Used in: [Apps](https://tidix.app/features/apps) ## Launch agent A background program that launchd, the macOS service manager, starts for a logged-in user, described by a property list in a `LaunchAgents` folder. Apps use them for updaters, sync and other helpers. Used in: [Apps](https://tidix.app/features/apps) ## Launch daemon A background program that launchd starts for the whole system rather than one user, even before anyone logs in, described by a property list in a `LaunchDaemons` folder. Daemons usually run as root, so changing one takes administrator rights. Used in: [Apps](https://tidix.app/features/apps) ## Logical CPU A processor that macOS can schedule work on. On Apple silicon each core is one logical CPU, while an Intel core with Hyper-Threading counts as two; Tidix draws a tile for each one. Used in: [Performance](https://tidix.app/features/performance) ## Login item An app or helper that opens automatically when you log in to your Mac. macOS manages login items in System Settings, under General. Used in: [Apps](https://tidix.app/features/apps) ## Memory pressure How hard macOS has to work to keep memory free, for example by compressing it or moving it to disk. Tidix shows the level macOS reports: normal, warning or critical. Used in: [Performance](https://tidix.app/features/performance) ## Paging How macOS moves memory pages between RAM and storage: a page-in reads a page from disk, and a page-out writes one out to make room. Steady page-outs are a sign that memory is running short. Used in: [Performance](https://tidix.app/features/performance) ## Pairing The one-time exchange of keys that lets a Mac and a device trust each other, so they reconnect later without asking. Forgetting a device deletes those keys, so it has to be paired again. Used in: [Bluetooth](https://tidix.app/features/bluetooth) ## Passkey (Bluetooth) A six-digit code used to [pair](https://tidix.app/glossary#pairing) a keyboard: the Mac shows it, you type it on the keyboard and press Return. A related check shows the same code on both sides for you to confirm. Used in: [Bluetooth](https://tidix.app/features/bluetooth) ## Performance cores The fast, more power-hungry cores of an Apple silicon chip, which take on demanding work. Tidix groups their tiles under Performance cores, with the group's average load. Used in: [Performance](https://tidix.app/features/performance) ## Process priority How much CPU time a busy process gets next to the others, set by its nice value from -20 (highest priority) to 20 (lowest); most processes run at 0. Raising the nice value makes a process yield to the rest, and only root can lower it again. Used in: [Processes](https://tidix.app/features/processes) ## Process sample A short recording of what each thread of a process is doing, taken many times a second, that shows which functions it spends its time in. Tidix's Sample runs macOS's `sample` tool for 3 seconds and opens the report as a text file. Used in: [Processes](https://tidix.app/features/processes) ## Process signal A short message macOS delivers to a process, such as `SIGTERM` (quit cleanly), `SIGKILL` (stop at once, cannot be caught) or `SIGSTOP` (pause). In Tidix, Quit sends `SIGTERM` and Force Quit sends `SIGKILL`. Used in: [Processes](https://tidix.app/features/processes) ## Process tree Processes arranged by parent, each one under the process that started it; on a Mac most of them descend from `launchd`, the first process the kernel starts. In Tidix, the **Process tree** button shows the Processes list this way. Used in: [Processes](https://tidix.app/features/processes) ## Related files Files an app keeps outside its own bundle, mostly in `~/Library`: support folders, caches, preferences, containers, logs, saved window state and cookies. Dragging the app to the Trash leaves them behind. Used in: [App details](https://tidix.app/features/app-details) ## RSSI Received Signal Strength Indicator: how strong a device's radio signal arrives, in dBm. Readings are negative, and closer to zero is stronger, so -50 dBm beats -80 dBm. Used in: [Bluetooth](https://tidix.app/features/bluetooth) ## Startup item Anything set to start on its own when your Mac starts up or you log in: login items, launch agents and daemons, and the extensions apps install. Tidix lists them in the Startup view of its Apps page. Used in: [Apps](https://tidix.app/features/apps) ## System extension Code an app installs to extend macOS from outside the kernel, such as a network filter, a security tool or a DriverKit driver. It replaces many kernel extensions and usually needs your approval in System Settings before it runs. Used in: [Apps](https://tidix.app/features/apps) ## Wakeups How often a process's threads wake up to run, which keeps the processor from resting and costs energy. Tidix's Wakeups/s column counts context switches per second, an approximation of that activity rather than a direct wakeup count. Used in: [Processes](https://tidix.app/features/processes)