The image depicts meshed silhouettes of various things.The original image is an OCAL clipart called "Enter FOSSASIA 2016 #IoT T-shirt Design Contest" uploaded by "openclipart".Thanks.
Source Yamachem
Prismatic Abstract Geometric Background 4 No Black
Source GDJ
Like the name says, light and gray, with some small dots and circles.
Source Brenda Lay
Dark, square, clean and tidy. What more can you ask for?
Source Jaromír Kavan
Seamless pattern formed from a tile that can be had by selecting the rectangle in Inkscape and using shift-alt-i.
Source Firkin
Prismatic Hexagonalism Pattern No Background
Source GDJ
ZeroCC tileable stone texture, edited from pixabay, CC0
Source Sojan Janso
Made by distorting a simple pattern using the 'sin waves' plugin for Paint.net and vectorising in Vector Magic
Source Firkin
Prismatic Isometric Cube Extra Pattern No Background
Source GDJ
Lovely light gray floral motif with some subtle shades.
Source GraphicsWall
Sharp pixel pattern looking like some sort of fabric.
Source Dmitry
A hint of orange color, and some crossed and embossed lines.
Source Adam Anlauf
Just to prove my point, here is a slightly modified dark version.
Source Atle Mo
From a drawing in 'Sun Pictures of the Norfolk Broads', Ernest Suffling, 1892.
Source Firkin
A seamless pattern formed from a tile that can be had in Inkscape by selecting the rectangle and using shift+alt+i.
Source Firkin
Remixed from a drawing in 'Hungary. A guide book. By several authors', 1890.
Source Firkin
Dark squares with some virus-looking dots in the grid.
Source Hugo Loning
A seamlessly tileable pink background texture.
Source V. Hartikainen
A bit of scratched up grayness. Always good.
Source Dmitry
Prismatic Rounded Squares Grid 3 No Background
Source GDJ
This was formed by distorting an image of a background on Pixabay.
Source Firkin
Plywood Web Background background image for use in web design.
Source V. Hartikainen