Seva means selfless service: action done for others with no expectation of payment, credit, or even thanks. In Sikhi, it isn't a side activity. It's one of the central ways a person grows and connects with the Divine.
The idea is simple to state and demanding to live. The more completely you can serve without your ego attached to the outcome, without needing to be seen, praised, or repaid, the more it changes you from the inside.
ਵਿਚਿ ਦੁਨੀਆ ਸੇਵ ਕਮਾਈਐ॥ ਤਾ ਦਰਗਹ ਬੈਸਣੁ ਪਾਈਐ॥
Vich duneeaa sev kamaa-ee-ai, taa dargeh baisan paa-ee-ai
"Within this world, do seva, only then will you find a seat in the Court of the Lord."
Guru Granth Sahib Ji, Ang 26This verse places seva firmly inside ordinary life, "vich duneeaa," within the world. Not in a temple alone, not in a special place set apart. Wherever you already are is where seva happens.
ਸੇਵਾ ਕਰਤ ਹੋਇ ਨਿਹਕਾਮੀ ॥ ਤਿਸ ਕਉ ਹੋਤ ਪਰਾਪਤਿ ਸੁਆਮੀ ॥
Sayvaa karat ho-ay nihkaamee, tis ka-o hot paraapat su-aamee
"One who performs selfless service, without thought of reward, shall attain his Lord and Master."
Guru Granth Sahib Ji, Ang 286True seva isn't measured by how grand the gesture looks. It's measured by whether reward was ever part of the reason for doing it.
ਨੀਚਹੁ ਨੀਚੁ ਨੀਚੁ ਅਤਿ ਨਾਨ੍ਹ੍ਹਾ ਹੋਇ ਗਰੀਬੁ ਬੁਲਾਵਉ ॥੧॥ ਰਹਾਉ ॥
Neechahu neech neech at naanhaa ho-ay gareeb bulaavo
"Become the lowest of the low, the very least of the tiny, and speak in utmost humility."
Guru Granth Sahib Ji, Ang 529Seva is tied directly to humility. Not doing it to be seen as great, but doing it while seeing yourself as no more important than the person you're serving.
ਘਾਲਿ ਖਾਇ ਕਿਛੁ ਹਥਹੁ ਦੇਇ॥ ਨਾਨਕ ਰਾਹੁ ਪਛਾਣਹਿ ਸੇਇ॥
Ghaal khaa-ay kichh hathahu day-ay, Naanak raahu pachhaaneh say-ay
"One who works for what he earns, and gives some of it away with his own hands, O Nanak, he alone knows the true path."
Guru Granth Sahib Ji, Ang 1245Seva, here, sits alongside an honest working life, not instead of it, not at the total expense of it. The hand that earns and the hand that gives are the same hand.
ਸੋ ਜਪੁ ਤਪੁ ਸੇਵਾ ਚਾਕਰੀ ਜੋ ਖਸਮੈ ਭਾਵੈ ॥
So jap tap sevaa chaakaree jo khasmai bhaavai
"That is chanting and meditation, work and selfless service, which is pleasing to our Lord and Master."
Guru Granth Sahib Ji, Ang 1247Seva isn't separate from simran here. The same verse holds chanting, meditation, work, and service together as one thing, judged by whether it pleases the Lord, not by which category it falls into.
This is the foundation everything else on this site builds from. The next question is how these same hands keep serving in Chardi Kala, giving, faithful, and rooted in Naam.