SOLID yana tsaye don saitin ƙa'idodi na asali a cikin ƙirar software da ake amfani da su don ƙirƙirar tsarin da za'a iya kiyayewa, daɗaɗɗa, da sassauƙa. SOLID gagara ne da aka samar da haruffan farko na waɗannan ka'idoji guda biyar:
S- Single Responsibility Principle
Aji ko module yakamata ya kasance yana da alhakin guda ɗaya kawai. Wannan yana taimakawa cikin sauƙin kiyayewa da gyara lamba ba tare da shafar wasu ayyuka ba.
O- Open/Closed Principle
Lambar ya kamata ta kasance a buɗe don tsawaita(ƙara sabbin abubuwa) amma rufe don gyarawa(ba canza lambar da ke akwai ba). Wannan yana ƙarfafa amfani da gado, musaya, ko wasu hanyoyin haɓaka don ƙara sabbin abubuwa ba tare da canza lambar da ke akwai ba.
L- Liskov Substitution Principle
Abubuwan da ke cikin aji dole ne su kasance a musanya su ga abubuwan ajin iyaye ba tare da sun shafi daidaitaccen shirin ba. Wannan yana tabbatar da cewa an aiwatar da gado cikin aminci kuma daidai.
I- Interface Segregation Principle
Yana da kyau a sami ƙanana da ƙayyadaddun musaya maimakon babban haɗin gwiwa tare da hanyoyi da yawa. Wannan yana taimakawa guje wa tilastawa azuzuwan aiwatar da hanyoyin da ba dole ba.
D- Dependency Inversion Principle
Matsakaicin matakan ƙima bai kamata ya dogara da ƙananan matakan ba. Dukansu ya kamata su dogara da abstractions. Wannan ka'ida tana ƙarfafa yin amfani da alluran dogaro don rage haɗaɗɗiyar haɗaɗɗiya tsakanin kayayyaki da sauƙaƙe tsarin don gwadawa da tsawaitawa.
SOLID ka'idoji suna haɓaka tsarin lambar, haɓaka haɓakawa, da rage haɗarin da ke tattare da canje-canje. Ana iya amfani da waɗannan ƙa'idodin a cikin harsunan shirye-shirye daban-daban da wuraren ci gaba.