This year, the cable channel Turner Classic Movies celebrated its 25th anniversary as the home where movie lovers can indulge in cinematic nostalgia. In some ways the network has kept many facets the same — all movie presentations remain commercial-free, for one, and fans continue to look forward to programming staples such as Summer Under the Stars (daylong marathons spotlighting movie stars) and “TCM Remembers” (an end-of-year in memoriam montage).

But TCM has not been resistant to change over the years, and on Monday, it announced a historic one: Beginning Sunday, the film historian and preservationist Jacqueline Stewart will step in to introduce the long-running weekly programming series Silent Sunday Nights. While in the past prominent figures such as Ava DuVernay and Spike Lee have served as guest programmers, Stewart will be the network’s first black host. (From 2016 to 2018, Tiffany Vazquez appeared on TCM as the channel’s first woman and person of color to host.)

Stewart, a professor at the University of Chicago specializing in black cinema and silent film history, might already be a familiar name (and face) to some hard-core TCM enthusiasts: In 2016 she appeared alongside the longtime host Ben Mankiewicz to introduce the companion series to “Pioneers of African-American Cinema,” a box set of short and feature films from the early 20th century that she helped curate. She was also a panelist at the TCM Film Festival in 2018 and 2019.

During a recent phone conversation, Stewart discussed film preservation in the age of streaming and how she plans to bring her expertise to her new role. These are edited excerpts from that conversation.