Wienie tot ze neet in ‘n besmette cel zien of in ‘t proces ‘n cel te besmette bestaon virusse in ‘n staot vaan oonaofhenkeleke deiltjes, of virions, dee bestaon oet ‘t genetisch mattriaol (DNA of RNA), ‘n eiwit laog genaomd capsid, en in sommege gevalle ‘n boetense envelop vaan lipides.