A-spec or A-spectrum is an umbrella term, describing all identities that fall on the asexual spectrum and aromantic spectrum. One does not need to be part of both spectrums to be a-spec. The term allows people to talk about those on the ace-spectrum and those on the aro-spectrum at the same time, as the two groups share many common experiences. It is also a useful term for those who are both ace-spec and aro-spec.
In addition to asexuals and aromantics a-spec identities include but are not limited to demisexual/romantic, greyasexual/greyromantic, lithosexual/romantic, fraysexual/romantic, and similar identities.
Controversy
According to some individuals, particularly exclusionists using the word a-spec to mean ace/aro-spec is appropriating from autistic individuals. It's claimed that a-spec was previously used to mean "autistic-spectrum". However, there is no evidence that this term ever used before it's usage by ace/aro-spec people. The most common way people abbreviate autiistic-spectrum is with "asd" standing for "autism spectrum disorder" or similar "on the spectrum". These claims are often made by non-autistic people in an attempt to de-legitimizing the terms used by a-spec people.
Flag
The a-spec flag was created by Tumblr user The-Moon-Is-Aroace on March 25, 2019[1]. The compass rose in the middle is a symbol of how people all experience attraction in different ways. The green and purple are on opposite sides of the quadrant to show that asexuality and aromanticism are their own separate and independent identities, with the black and grey quadrants connecting them. Black represents the aroace community and grey represents grey aspec communities.