Q: Purgeble items??

I ran First Aid before and after installing Sierra. I had/have no problems with it. But after rebooting to run First Aid the second time under Memory is says 413.4 MB Purgeble. What am I supposed to purge??  I ran etrecheck, which says my system is excellent. Firestorm crashed because I didn't close it properly. I am not a techie and don't know what to purge or if i should mess with it. I have plenty of memory left.

EtreCheck version: 3.0.6 (315)

Report generated 2016-09-30 18:53:01

Download EtreCheck from https://etrecheck.com

Runtime 1:55

Performance: Excellent

Click the [Support] links for help with non-Apple products.

Click the [Details] links for more information about that line.

Problem: Other problem

Hardware Information: ⓘ

    iMac (21.5-inch, Late 2013)

    [Technical Specifications] - [User Guide] - [Warranty & Service]

    iMac - model: iMac14,3

    1 2.9 GHz Intel Core i5 CPU: 4-core

    8 GB RAM Upgradeable - [Instructions]

        BANK 0/DIMM0

            4 GB DDR3 1600 MHz ok

        BANK 1/DIMM0

            4 GB DDR3 1600 MHz ok

    Bluetooth: Good - Handoff/Airdrop2 supported

    Wireless: Unknown

Video Information: ⓘ

    NVIDIA GeForce GT 750M - VRAM: 1024 MB

        iMac 1920 x 1080

System Software: ⓘ

    macOS Sierra  10.12 (16A323) - Time since boot: less than an hour

Disk Information: ⓘ

    APPLE HDD HTS541010A9E662 disk0 : (1 TB) (Rotational)

        EFI (disk0s1) <not mounted> : 210 MB

        Recovery HD (disk0s3) <not mounted>  [Recovery]: 650 MB

        Macintosh HD (disk1) /  [Startup]: 999.03 GB (974.45 GB free)

            Core Storage: disk0s2 999.35 GB Online

USB Information: ⓘ

    Apple Inc. BRCM20702 Hub

        Apple Inc. Bluetooth USB Host Controller

    Apple Inc. FaceTime HD Camera (Built-in)

    Apple, Inc. Keyboard Hub

        Apple Inc. Apple Keyboard

    Mitsumi Electric Apple Optical USB Mouse

Thunderbolt Information: ⓘ

    Apple Inc. thunderbolt_bus

Gatekeeper: ⓘ

    Mac App Store and identified developers

System Launch Agents: ⓘ

    [not loaded]    6 Apple tasks

    [loaded]    178 Apple tasks

    [running]    87 Apple tasks

System Launch Daemons: ⓘ

    [not loaded]    42 Apple tasks

    [loaded]    165 Apple tasks

    [running]    96 Apple tasks

Launch Agents: ⓘ

    [loaded]    com.google.keystone.agent.plist (2016-07-12) [Support]

Launch Daemons: ⓘ

    [loaded]    com.google.keystone.daemon.plist (2016-09-02) [Support]

User Login Items: ⓘ

    iTunesHelper    Application  (/Applications/iTunes.app/Contents/MacOS/iTunesHelper.app)

Internet Plug-ins: ⓘ

    QuickTime Plugin: 7.7.3 (2016-09-13)

3rd Party Preference Panes: ⓘ

    None

Time Machine: ⓘ

    Time Machine not configured!

Top Processes by CPU: ⓘ

         4%    WindowServer

         2%    fontd

         1%    hidd

         0%    kernel_task

         0%    com.apple.AmbientDisplayAgent

Top Processes by Memory: ⓘ

    581 MB    kernel_task

    139 MB    Finder

    123 MB    mdworker(11)

    123 MB    mds_stores

    98 MB    WindowServer

Virtual Memory Information: ⓘ

    4.78 GB    Free RAM

    3.22 GB    Used RAM (1.63 GB Cached)

    0 B    Swap Used

Diagnostics Information: ⓘ

    Sep 30, 2016, 06:39:38 PM    Self test - passed

    Sep 30, 2016, 06:17:50 PM    ~/Library/Logs/DiagnosticReports/SLPlugin_2016-09-30-181750_[redacted].crash

        /Applications/FirestormOS-Releasex64.app/Contents/Resources/SLPlugin.app/Conten ts/MacOS/SLPlugin

    Sep 30, 2016, 06:17:47 PM    ~/Library/Logs/DiagnosticReports/Firestorm_2016-09-30-181747_[redacted].crash

        com.phoenixviewer.firestorm.viewer-oss - /Applications/FirestormOS-Releasex64.app/Contents/MacOS/Firestorm

    Sep 30, 2016, 05:25:03 PM    /Library/Logs/DiagnosticReports/Firestorm_2016-09-30-172503_[redacted].cpu_reso urce.diag [Details]

    Sep 29, 2016, 06:26:05 PM    ~/Library/Logs/DiagnosticReports/Firestorm_2016-09-29-182605_[redacted].crash

    Sep 29, 2016, 06:25:59 PM    ~/Library/Logs/DiagnosticReports/SLPlugin_2016-09-29-182559_[redacted].crash

    Sep 29, 2016, 04:38:13 PM    ~/Library/Logs/DiagnosticReports/SLPlugin_2016-09-29-163813_[redacted].crash

    Sep 29, 2016, 03:09:49 PM    ~/Library/Logs/DiagnosticReports/SLPlugin_2016-09-29-150949_[redacted].crash

    Sep 28, 2016, 06:55:22 PM    ~/Library/Logs/DiagnosticReports/SLPlugin_2016-09-28-185522_[redacted].crash

    Sep 28, 2016, 03:44:17 PM    ~/Library/Logs/DiagnosticReports/SLPlugin_2016-09-28-154417_[redacted].crash

    Sep 28, 2016, 10:13:01 AM    ~/Library/Logs/DiagnosticReports/SLPlugin_2016-09-28-101301_[redacted].crash

    Sep 27, 2016, 07:35:39 PM    ~/Library/Logs/DiagnosticReports/SLPlugin_2016-09-27-193539_[redacted].crash