HTTPS (HTTP Secure) wraps the HTTP application layer inside a TLS tunnel. Every request and response is encrypted: the target URL path, headers, and body are all hidden from network observers. Only the destination domain name (SNI) is visible in the TLS ClientHello before encryption begins.
For scrapers, HTTPS is the default for virtually all modern websites. The primary scraping implication is that HTTPS connections require a TLS handshake that adds latency (mitigated by connection pooling and session resumption) and exposes a TLS fingerprint. Using a proxy with HTTPS requires the proxy to perform a CONNECT tunnel, preserving end-to-end encryption, or to act as a TLS-terminating proxy (man-in-the-middle), which requires the scraper to trust the proxy's certificate.
HTTP Strict Transport Security (HSTS) causes browsers and scraping clients to automatically upgrade HTTP requests to HTTPS, preventing accidental plain-text connections.